Answer:Rolling friction is friction that acts on objects when they are rolling over a surface. Rolling friction is much weaker than sliding friction or static friction. This explains why most forms of ground transportation use wheels, including bicycles, cars, 4-wheelers, roller skates, scooters, and skateboards.
Explanation:
A spiral spring of 8cm extended to 9.2cm when a load of 1.6N is applied. what is the force constant of the spring, provided the elastic is not exceeded.
Explanation:
By Hooke's Law, Fe = kx.
Since Fe = 1.6N and x = 9.2cm - 8cm = 1.2cm,
k = Fe/x = 1.6N/1.2cm = 1.33N/cm.
The ancestors of horses possess feet with five digits . Over time with the development of grassland the digits fused and former hooves . What evolutionary advantage did this transformation serve
Answer:
It enabled them to run faster from predators.
Explanation:
The evolution of hooves from a five-digit feet enabled horses to run faster from predators as well as support their larger weights and longer legs. Hope this helped and have an awesome day! :)
It enabled them to run faster from predators. ]
Explanation: The evolution of hooves from a five-digit feet enabled horses to run faster from predators as well as support their larger weights and longer legs.
A stunt person jumps from the roof of a tall building, but no injury occurs because the person lands on a large, air-filled bag. Which one of the following best describes why no injury occurs?
A. The bag increases the amount of time during which the momentum is changing and reduces the average force on the person.
B. The bag increases the amount of time the force acts on the person and reduces the change in momentum.
C. The bag reduces the impulse to the person.
D. The bag provides the necessary force to stop the person.
E. The bag decreases the amount of time during which the momentum is changing and reduces the average force on the person.
Answer:
A stunt person jumps from the roof of a tall building, but no injury occurs because the person lands on a large, air-filled bag. Which one of the following best describes why no injury occurs?
The bag increases the amount of time during which the momentum is changing and reduces the average force on the person.
ANSWER: A
Answer:
A. The bag increases the amount of time during which the momentum is changing and reduces the average force on the person.
During stunts, people usually put an-air filled bag on the ground for safe landing and to prevent injuries.
Momentum is calculated by m* v where m is for mass and v is for velocity.
Force is directly proportional to momentum
F∝M
The bag in this scenario helps to increases the amount of time the force acts on the person. This implication means that there is a reduction in the change of momentum. Since Force and momentum have a directly proportional relationship then the Force taken to hit the floor is greatly reduced.
Read more on https://brainly.com/question/20362316
Which of the following is an opinion about friction?
It always acts in the opposite direction as the motion of the object.
It stops objects on Earth from staying in motion forever.
It slows objects down too much.
It happens any time two objects are in contact.
Help me out please-
You'll get 40 points
My opinion about friction is that It always acts in the opposite direction as the motion of the object.
What is friction?Friction refers to the resistance of motion of one object that is moving relative to another object. Fricton has many application but it has also many disadvantages.
So we can conclude that friction is always acts in the opposite direction as the motion of the object.
Learn more about friction here: https://brainly.com/question/24338873
Use the following free body diagram to answer questions 8 and 9:
8. Calculate the net force acting on the cart.
A 0N
B. +60N
C -60N
D. +240 N
9. Calculate the cart's rate of acceleration
A +60 m/s
B. +8 m/s
C.-2m/s
D. +2 m/s
Answer:
8 is c and 9 is b it is shown though the practice as god lol
Question 8
The net force acting on the cart is:
F = 150 N - 90 N
F = 60 N
Question 9
By the Newtons second law:
F = ma
Solving for a:
a = F/m
a = 60 N / 30 kg
a = 2 m/s²
A block that slides on a rough surface slows down and eventually stops. The reverse process never occurs. That is, a block at rest never begins to move and accelerate on a rough surface without the action of an external agent. The second situation is forbidden because it would violate:_________.
a) conservation of total energy
b) conservation of momentum
c) the first law of thermodynamics
d) the second law of thermodynamics
e) both the first and second law of thermodynamics
Gracias.
Answer:
d) the second law of thermodynamics
Explanation:
Here we take an example
The entropy represents a measurement of the energy dispersal in the system. Also, the campfire would an entropy example. The burning of the solid wood and then it became the ash, smoke and gases this all would be spread the energy to the outward as compared to the solid fuel
Therefore as per the given statement, the correct option is d.
Car 2 and Car 3 are driving down the road at the same speed. Car 1, going 15 m/s, has just passed Car 2 and is approaching Car 3 when he sees Person A standing in front of him. The driver of Car 1 quickly honks his horn as a warning, but does not brake. At the moment that Car 1 honks his horn, Person B is riding his bicycle, behind, but in the same direction as Car 1 at 7 m/s. Which person hears the highest frequency from the horn?
Answer:
Person A
Explanation:
Person A hears the highest frequency from the horn than Person B because Person A is present in front of a Car 1 while the Person B present behind the Car 1. The car horn is present at the front so the Person A will hear the highest frequency from the horn as compared to Person B which hears lower frequency from the horn. If the horn is present at the back side so Person B will hear highest frequency from the horn.
Just do the attachment
Answer: your answer is B I know that's what you picked but I believe it is correct! look below...
Explanation: A solution is made when one substance called the solute "dissolves" into another substance called the solvent. Dissolving is when the solute breaks up from a larger crystal of molecules into much smaller groups or individual molecules.
In order to form a solution, the solute must be surrounded, or solvated, by the solvent. Solutes successfully dissolve into solvents when solute-solvent bonds are stronger than either solute-solute bonds or solvent-solvent bonds.
BRAINLIEST?
Calculate the change in entropy of 0.020 kg of ice when it melts at 0.0°C. The heat of fusion of ice is 3.36 x 10'J/kg.
Answer:
S = 2461.53 [kJ]
Explanation:
The change in entropy in a process such as melting can be calculated by means of the following expression.
[tex]S=\frac{H*m}{T}[/tex]
where:
S = entropy [kJ]
H = fusion heat = 3.36*10¹ [J/kg]
m = mass = 0.02 [kg]
T = temperature in kelvin = 273 [K]
[tex]S = \frac{0.02*3.36*10^{1} }{(273+0)}\\S = 2461.53 [kJ][/tex]
A girl rides her bike at 15 m/s for 20 s. How far does she travel in that time?
We are given:
Initial Velocity(u) = 15 m/s
Time interval(t) = 20s
Solving for the distance covered:
Since the girl keeps riding her bike at 15 m/s, her speed is constant and hence, acceleration of the bike is 0 m/s²
acceleration(a) = 0 m/s²
We know that:
s = ut + 1/2(at²) [second equation of motion]
s = (15)(20) + 1/2(0)(400) [plugging the values]
s = 150 + 0
s = 300 m
Hence, the girl covered 300 m in 20 seconds
2. Using Graph 2, calculate the net force experienced by the particle between 4 and 6 seconds. The
particle has a mass of 0.25 kg.
A +5.0 N
B. +0.5 N
C. -0.5 N
D. -2.0 N
Using Newtons Second Law:
F = m×a
F = (0.25 kg)(-2 m/s²)
F = -0.5 N
The correct option is CLook at this model of an atom. Where are the protons located and how many are there?
Answer:
protons are in the nucleus .
Explanation:
there are 6 protons
Select the correct answer.
Derick has been working as a first responder since many years. His primary responsibility at a crime scene is to question witnesses and gather
useful information from the scene. Which of these first responder career roles does Derick fit into?
OA paramedic
OB. police officer
Oc. fire truck driver
OD. firefighter
Answer:
Police officer
Explanation:
Because police officers wants to gather information on what happens and question people to know everything. That is what Derick is doing
Please help! What kind of energy is produce when solar panel to lightbulb filament?
Answer:
electrical energy
Explanation:
sorry I'm really tired but trust me on this one
Answer:
electrical to thermal and light
Explanation:
The FitnessGram Pacer Test is a multistage aerobic capacity test that progressively gets more difficult as it continues. The 20 meter pacer test will begin in 30 seconds. Line up at the start. The running speed starts slowly, but gets faster each minute after you hear this signal. A single lap should be completed each time you hear this sound. Remember to run in a straight line, and run as long as possible.
A 300 g bird flying along at 6.0 m/s sees a 10 g insect heading straight toward it with a speed of 30 m/s. the bird opens its mouth wide and enjoys a nice lunch. What is the bird's speed immediately after swallowing?
Answer:
6.77m/s
Explanation:
Using the law of conservation of momentum
m1u1 + m2u2 = (m1+m2)v
m1 and m2 are the masses of the object
u1 and u2 are the velocities before collision
v is the final collision
Given
m1 = 300g = 0.3kg
u1 = 6.0m/s
m2 = 10g = 0.01kg
u2 = 30m/s
Required
The bird's speed immediately after swallowing v
Substitute the given values into the formula
m1u1 + m2u2 = (m1+m2)v
0.3(6) + 0.01(30) = (0.3+0.01)v
1.8+0.3 = 0.31v
2.1 = 0.31v
v = 2.1/0.31
v = 6.77m/s
Hence the bird's speed immediately after swallowing is 6.77m/s
A thin, uniform stick of mass M and length L is at rest on a flat, frictionless surface to which one end of it is pinned. A small mass m traveling at speed v collides with and attaches to the stick at a distance 2L/3 away from the end through which it is pinned to the surface. (a) Find an expression for the moment of inertia of the stick mass object after the collision. (b) Find an expression for the final angular speed of the combined object
Answer:
a) I = ([tex]\frac{M}{3}[/tex] + [tex]\frac{4m}{9}[/tex]) L² , b) w = (\frac{27 M}{18 m} + 2)⁻¹ Lv₀
Explanation:
a) The moment of inertia is a scalar that represents the inertia in circular motion, therefore it is an additive quantity.
The moment of inertia of a rod held at one end is
I₁ = 1/3 M L²
The moment of inertia of the mass at y = L
I₂ = m y²
The total inertia method
I = I₁ + I₂
I = \frac{1}{3} M L² + m (\frac{2}{3} L)²
I = ([tex]\frac{M}{3}[/tex] +[tex]\frac{4m}{9}[/tex] ) L²
b) The conservation of angular momentum, where the system is formed by the masses and the bar, in such a way that all the forces during the collision are internal.
Initial instant. Before the crash
L₀ = I₂ w₀
angular and linear velocity are related
w₀ = y v₀
w₀ = [tex]\frac{2}{3}[/tex]L v₀
L₀ = I₂ y v₀
Final moment. After the crash
[tex]L_{f}[/tex] = I w
how angular momentum is conserved
L₀ = L_{f}
I₂ y v₀ = I w
substitute
m ([tex]\frac{2L}{3}[/tex])² (\frac{2L}{3} v₀ = ([tex]\frac{M}{3}[/tex] +[tex]\frac{4m}{9}[/tex] ) L² w
[tex]\frac{6}{27}[/tex] m L³ v₀ = ([tex]\frac{M}{3}[/tex] +[tex]\frac{4m}{9}[/tex] ) L² w
[tex]\frac{6}{27}[/tex] m L v₀ = ([tex]\frac{M}{3}[/tex] +[tex]\frac{4m}{9}[/tex] ) w
L v₀ = [tex](\frac{27 M}{18 m} + 2)[/tex] w
w = (\frac{27 M}{18 m} + 2)⁻¹ Lv₀
A car of mass 1150 kg drives in a circle of radius 44 m. If the car has a speed of 13 m/s, what is the
centripetal force acting on the car?
Answer:
4417
i think because
mv^2/r is centripetal force
1. A 15 kg chair initially at rest on a horizontal floor requires 125 N to set it in motion, Ong
the chair is in motion, a 95 kg force keeps it moving at constant veloclty,
a Find the coefficient of static friction between the chair and the floor,
Answer:
μ = 0.849
Explanation:
In order to solve this problem we must remember that the friction force is defined as the product of the coefficient of friction by the normal force. And normal force is defined as the component of force in the opposite direction to the weight of the body (chair).
As in the y axis there is no movement we can say that the sum of the forces on the chair is equal to zero.
∑Fy = 0
[tex]N-W=0[/tex]
where:
N = normal force [N] (units of Newtons)
W = weight of the chair = m*g [N]
m = mass = 15 [kg]
g = gravity acceleration = 9.81 [m/s²]
[tex]N=m*g\\N=15*9.81\\N=147.15 [N][/tex]
Now the key to solving this problem is to understand that we start applying force on the horizontal component until the chair starts to move at this moment the friction component is calculated with the static friction coefficient. As the chair doesn't move we can say that the sum of force in the horizontal direction is equal to zero.
∑Fx = 0
[tex]F -f_{force} = 0[/tex]
F = force applied = 125 [N]
fforce = friction force = μ*N
μ = friction coefficient (static)
N = normal force = 147.15 [N]
[tex]125-u*147.15=0\\u = 125/147.15\\u = 0.849[/tex]
True/False: The core, mantle, and crust explanation for the Earth's layers is outdated and now we use the 5 layer explanation. *
Answer:
False
Explanation:
We still use the old way. It's easier to understand the old way, and its NOT outdated.
two spheres A and B are projected off the edge of a 1.0 m high table with the same horizontal velocity . sphere A has a mass of 20.g and sphere B has a mass of 10.g.
If both spheres leave the edge of the table at the same instant, sphere A will land
a. at some time after sphere B.
b. at the same time as sphere B.
c. at some time before sphere B.
d. There is not enough information to decide.
__ 6. If both spheres leave the edge of the table at the same instant, sphere A hits the floor at the spot marked X. Sphere B will hit the floor
a. at some point between the edge of the table and X.
b. at some point past X.
c. at the same distance from the table as X.
d. there is not enough information to decide.
Answer:
C. and D.
C. becuase A is heavier so it will land first
Use the following information to answer questions 4 and 5:
A rock is launched vertically into the air at a velocity of 14.75 m/s.
4. Toby claims that the rock must come to rest before it can fall back towards the ground. Is Toby
correct?
A. Toby is correct because the rock is experiencing a negative acceleration, causing its negative
velocity to increase until the rock reaches a velocity of O m/s before becoming positive.
B. Toby is correct because the rock is experiencing a negative acceleration, causing its positive
velocity to decrease until the rock reaches a velocity of O m/s before becoming negative.
C. Toby is incorrect because the rock is experiencing a positive acceleration, causing its positive
velocity to increase in magnitude.
D. Toby is incorrect because the rock is experiencing a negative acceleration, causing its positive
velocity to increase in magnitude.
5. Calculate the time it takes for the rock to reach its maximum height.
A. 1.50 seconds
B. 2.47 seconds
C. 3.00 seconds
D. 4.94 seconds
Question 4
B. Toby is correct because the rock is experiencing a negative acceleration, causing its positive velocity to decrease until the rock reaches a velocity of O m/s before becoming negative.
Question 5
At the maximum height, velocity is 0, so:
v = v₀ - gt
0 = 14.75 - 9.8t
t = 14.75/9.8
t = 1.5 s (OPTION A)
4). In the given situation, the assertion that could be made regarding Toby would be:
B). Toby is correct because the rock is experiencing a negative acceleration, causing its positive velocity to decrease until the rock reaches a velocity of O m/s before becoming negative.
5). The time that would be taken by the rock to attain its greatest height would be:
1.5 second
4). Tobby correctly states as rock would be undergoing a -ve acceleration which leads its +ve velocity to fall by the time rock attains the velocity of 0 m/s.
Thus, option B is the correct answer.
5). Given that,
Initial velocity([tex]v_{0}[/tex]) = 14.75 m/s
As we know,
Velocity remains 0 m/s at the greatest height,
So,
Velocity(v) [tex]= v_{0} - gt[/tex]
where
[tex]0 = 14.75 - 9.8t[/tex]
⇒ [tex]t = 14.75/9.8[/tex]
∵ [tex]t = 1.5 s[/tex]
Learn more about "Velocity" here:
brainly.com/question/18084516
How do the potential and kinetic energy change as the sled moves down the slope?
IF YOU DID SLED WARS WORKSHEET HELP ME PLEASE
Answer:
when a sled is moving, the kinetic energy is changing beacuse of the speed and mass. its cause the sled to move, and changes because you aren't at a constant speed. potential energy changes when you get on. because you are adding more weight causing the gravity to change.
Three identical train cars, coupled together are rolling east at 2.0 m/s. A fourth car traveling east at 4.0 m/s catches up with the three and couples to make a fourcar train. A moment later the train cars hit a fifth car that was at rest on the tracks, and it couples to make a five car train. What is the speed of the five car train?
Answer:
The value is [tex]v = 2 \ m/s[/tex]
Explanation:
From the question we are told that
The velocity of the each of the three cars is [tex]u_1 = u_2 = u_3 = 2 \ m/s[/tex]
The velocity of the fourth car is [tex]u_4 = 4 \ m/s[/tex]
The initial velocity of the fifth car [tex]u_5 = 0 \ m/s[/tex]
Generally from the law of momentum conservation we have that
[tex]m_1 u_1 + m_2 u_2 + m_3 u_3 +m_4u_4 + m_5u_5 = [m_1 + m_2 + m_3 +m_4+ m_5]v[/tex]
Given that the cars are identical then their mass will be the same
i.e
[tex]m_1 =m_2 = m_3 = m_4 = m_5 = m[/tex]
=> [tex][u_1 + u_2 + u_3 +u_4 + u_5]m = 5mv[/tex]
=> [tex]2+ 2 + 2 +4 + 0 = 5v[/tex]
= > [tex]v = 2 \ m/s[/tex]
Help please I would appreciate it
Answer:
i think the red runner travels greater distance ie.40 m
Explanation:
although ,the blue one travels 21 m but in the backward direction .so the correct ans is "the red runner travels 40 m"
hita's Question Bank- CTEVT
Baishakh] Q.No. 12 What is radiocarbon dating?
VER QUESTIONS
"Radiocarbon dating is a method for determining the age of an object containing organic material by using the properties of radiocarbon."
Answer:
well for me I think
Explanation:
The use of carbon 12 to tell the age of substances
b) A satellite with mass m orbits the Earth at a radius r. A second satellite also with mass m orbits the
Earth at twice the radius.
How does the force of Earth's gravity acting on the two satellites
compare? PLEASE HURRY
Answer:
So, given the eqn Fg=G(m1+m2/r^2) where G is the gravitational constant, m is the mass of the satellite and m2 is the mass of the earth and r is the distance from earth to the satellite, the force of earths gravity should be quartered.
Cause (2r)^2 gets turned into (4r^2) where 4r^2 is compared to r^2
Explanation:
What are some ways that the Greeks demonstrated their passion for public life?
Answer:
The Greeks had drama and arts competitions that were considered very popular, and important in society.
Explanation:
hope it helps!
Which has a greater force: a semi-truck at rest or a moving bicycle?
Although the semi truck certainly has a larger mass, it is not in motion and therefore does not have any momentum. The bicycle however has both mass and velocity and therefore has the larger momentum of the pair.
2. A car accelerates at a rate of 1.4 m/s. Find the mass of the car if a 2250 N net force is
required to produce this acceleration.
Answer:
1607.14 kgExplanation:
The mass of the car can be found by using the formula
[tex]m = \frac{f}{a} \\ [/tex]
f is the force
a is the acceleration
From the question we have
[tex]m = \frac{2250}{1.4} \\ = 1607.14285...[/tex]
We have the final answer as
1607.14 kgHope this helps you
A 782-kg satellite is in a circular orbit about Earth at a height above Earth equal to Earth's mean radius. (a) Find the satellite's orbital speed. 9.82278e7 Incorrect: Your answer is incorrect. Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. m/s (b) Find the period of its revolution. h (c) Find the gravitational force acting on it.
Answer:
a) v = 5.59x10³ m/s
b) T = 4 h
c) F = 1.92x10³ N
Explanation:
a) We can find the satellite's orbital speed by equating the centripetal force and the gravitation force as follows:
[tex] F_{c} = F_{G} [/tex]
[tex]\frac{mv^{2}}{r + h} = \frac{GMm}{(r + h)^{2}}[/tex]
[tex] v = \sqrt{\frac{gr^{2}}{r+h} [/tex]
Where:
g is the gravity = 9.81 m/s²
r: is the Earth's radius = 6371 km
h: is the satellite's height = r = 6371 km
[tex]v = \sqrt{\frac{gr^{2}}{2r}} = \sqrt{\frac{gr}{2}} = \sqrt{\frac{9.81 m/s^{2}*6.371 \cdot 10^{6} m}{2}} = 5.59 \cdot 10^{3} m/s[/tex]
b) The period of its revolution is:
[tex] T = \frac{2\pi}{\omega} = \frac{2\pi (r + h)}{v} = \frac{2\pi (2*6.371 \cdot 10^{6} m)}{5.59 \cdot 10^{3} m/s} = 14322.07 s = 4 h [/tex]
c) The gravitational force acting on it is given by:
[tex] F = \frac{GMm}{(r + h)^{2}} [/tex]
Where:
M is the Earth's mass = 5.97x10²⁴ kg
m is the satellite's mass = 782 kg
G is the gravitational constant = 6.67x10⁻¹¹ Nm²kg⁻²
[tex] F = \frac{GMm}{(r + h)^{2}} = \frac{6.67 \cdot 10^{-11} Nm^{2}kg^{-2}*5.97 \cdot 10^{24} kg*782 kg}{(2*6.371 \cdot 10^{6} m)^{2}} = 1.92 \cdot 10^{3} N [/tex]
I hope it helps you!