Answer:
Work is the energy needed to apply a force to move an object a particular distance, where force is parallel to the displacement. Power is the rate at which that work is done.
Answer: Work is the energy needed to apply a force to move an object a particular distance, where force is parallel to the displacement. Power is the rate at which that work is done.
Explanation:
5. A car advertisement states that a certain car can accelerate from rest to 70 m/s in 7
seconds. Find the car's average acceleration.
O-0.10 m/s^2
10 m/s^2
-10 m/s^2
O 0.10 m/s^2
Answer:
The car's average acceleration is [tex]10\ m/s^2[/tex].
Explanation:
Constant Acceleration Motion
It's a type of motion in which the velocity of an object changes by an equal amount in every equal period of time.
Being vo the initial speed, a the constant acceleration, vf the final speed, and t the time, the following relation applies:
[tex]v_f=v_o+at[/tex]
If we need to find the acceleration, we solve the above equation for a:
[tex]\displaystyle a=\frac{v_f-v_o}{t}[/tex]
The car accelerates from rest (vo=0) to vf=70 m/s in t=7 seconds. Substitute the values into the formula:
[tex]\displaystyle a=\frac{70-0}{7}=\frac{70}{7}=10[/tex]
[tex]a=10\ m/s^2[/tex]
The car's average acceleration is [tex]10\ m/s^2[/tex].
Note: The choices are not very clear, but the second choice seems to be the correct answer.
A car at the top of a ramp starts from rest and rolls to the bottom of the ramp, achieving a certain final speed. If you instead wanted the car to achieve twice as much speed at the bottom of the ramp, how high should the ramp be compared to the first case
Answer:
It must be 4 times high.
Explanation:
Assuming that the car can be treated as a point mass, and that the ramp is frictionless, the total mechanical energy must be conserved.This means, that at any time, the following must be true:ΔK (change in kinetic energy) = ΔU (change in gravitational potential energy)⇒ [tex]m*g*h = \frac{1}{2} * m*v^{2}[/tex]
Let's call v₁, to the final speed of the car, and h₁ to the height of the ramp.So, at the bottom of the ramp, all the gravitational potential energy
must be equal to the kinetic energy of the car (Defining the bottom of
the ramp as our zero reference for the gravitational potential energy):
[tex]m*g*h_{1} = \frac{1}{2} * m*v_{1} ^{2}[/tex] (1)
Now, let's do v₂ = 2* v₁Replacing in (1) we get:[tex]m*g*h_{2} = \frac{1}{2} * m*(2*v_{1}) ^{2}[/tex] (2)
Dividing (2) by (1), and rearranging terms, we get:h₂ = 4* h₁D
5. Mariam driving at a speed of 20.0 m/s applies
brakes close to a signal and travels a distance of
200 m before coming to rest. What was her
acceleration?
A. -0.50 m/s2
B. -0.70 m/s2
C. -1.00 m/s2
D. -2.00 m/s2
6. A trollen at rest is nushed to accelerate at a
Answer:
maibi.... D
Explanation:
I think is D
3.what does this stand for ??
Answer:
see below
Explanation:
The triangle stands for the change in
We would change the change in x
Answer:
Δ This is the symbol of Delta which means Change
and x is length/distance/position.
Thus, Δx stands for Change in length/distance/position.
-TheUnknownScientist
A tower crane has a hoist motor rated at 159 hp. If the crane is limited to using 72.0 % of its maximum hoisting power for safety reasons, what is the shortest time in which the crane can lift a 5550 kg load over a distance of 89.0 m
Answer:
The value is [tex]t = 56.68 \ s [/tex]
Explanation:
From the question we are told that
The rating of the hoist motor is [tex]k = 159hp = 159 *746 =118614 \ W[/tex]
The percentage of it power used is [tex]z = 0.72 * 118614=85402.08 \ W[/tex]
The mass of the load is m = 5550 kg
The distance is h = 89.0 m
The potential energy required to lift the load through that distance is
[tex]E = m * g * h[/tex]
=> [tex]E = 5550 * 9.8 * 89.0[/tex]
=> [tex]E = 4840710 \ J[/tex]
Generally the time taken is mathematically represented as
[tex]t = \frac{E}{ z}[/tex]
=> [tex]t = \frac{4840710}{ 85402.08}[/tex]
=> [tex]t = 56.68 \ s [/tex]
Help me please :)
Answer the following questions to explain the relationship between electricity and magnetism.
• What are the critical components of an electromagnet and what purpose do they each serve?
• How can the strength of an electromagnet be changed?
• Why is an electromagnet considered a temporary magnet?
Answer the following questions about motors and generators.
• What components are needed for a generator to produce electric current?
• Describe motors and generators in terms of energy input and output.
HELP MEEEEEEEE
Decide if the following statements would be found in the Motor or Generator. Answers can be found at the end of the 3.07 Reading.
Statement Motor or Generator?
Answer:
R u from k12?? i am XD add me on discord my username is Hot Boy#1650
Explanation:
A 1400.0 kg car crests a 3200.0 m pass in the mountains and briefly comes to rest. The car descends 1000 m before climbing and cresting a 2800 m pass. (a) Neglecting friction, what should the speed of the car be at the top of the second pass? (b) Find the actual speed of the car if the work due to nonconservative forces is – 5 x106 J.
Answer:
a) v = 88.54 m/s
b) vf = 26.4 m/s
Explanation:
Given that;
m = 1400.0 kg
a)
by using the energy conservation
loss in potential energy is equal to gain in kinetic energy
mg × ( 3200-2800) = 1/2 ×m×v²
so
1400 × 9.8 × 400 = 0.5 × 1400 × v²
5488000 = 700v²
v² = 5488000 / 700
v² = 7840
v = √7840
v = 88.54 m/s
b)
Work done by all forces is equal to change in KE
W_gravity + W_non - conservative = 1/2×m×(vf² - vi²)
we substitute
1400 × 9.8 × ( 3200-2800) - (5 × 10⁶) = 1/2 × 1400 × (vf² -0 )
488000 = 700 vf²
vf² = 488000 / 700
vf² = 697.1428
vf = √697.1428
vf = 26.4 m/s
What equation relates mechanical energy, thermal energy, and total energy when there is friction present in a system?
The diagram shows two forces acting on the dog. What are these two forces
Answer:
kenietic and potential i guess
Explanation:
This diagram shows two different forces acting on a skateboarder. The
combined mass of the skateboard and the person is 81.5 kg. Based on this
information, what is the acceleration of the skateboarder?
Air resistance = 11.40 N
mi
Applied force = 52.80
A. 0.51 m/s2 to the left
O B. 1.94 m/s2 to the right
O C. 1.94 m/s2 to the left
O D. 0.51 m/s2 to the right
Answer:
Option D. 0.51 m/s² to the right.
Explanation:
The following data were obtained from the question:
Force applied (Fₐ) = 52.8 N
Force resistance (Fᵣ) = 11.4 N
Mass = 81.5 kg
Acceleration (a) =.?
Next, we shall determine the net force (Fₙ). This can be obtained as follow:
Force applied (Fₐ) = 52.8 N
Force resistance (Fᵣ) = 11.4 N
Net force (Fₙ) =?
Fₙ = Fₐ – Fᵣ
Fₙ = 52.8 – 11.4
Fₙ = 41.4 N to the right
Finally, we shall determine the acceleration of the skateboarder as show below:
Net force (Fₙ) = 41.4 N to the right
Mass = 81.5 kg
Acceleration (a) =..?
F = ma
41.4 = 81.5 × a
Divide both side by 81.5
a = 41.4 / 81.5
a = 0.51 m/s² to the right.
Thus, the acceleration of the skateboarder is 0.51 m/s² to the right.
Answer: .51 to the right
Explanation:
The Intensity level of a loud saw is 100 db at a distance of 5m. At what distance would the level be 80 db
Answer:
50 m
Explanation:
The relationship between the intensity of sound in dB and distance is given by the formula:
[tex]B_2=B_1+20log(\frac{R_1}{R_2} )\\\\Where \ B_2\ is \ the\ sound\ intensity\ at\ distance\ R_2\ and\\B_1\ is \ the\ sound\ intensity\ at\ distance\ R_1\ \\\\Given\ that: B_1=100\ dB, R_1=5\ m, B_2=80\ dB\\\\B_2=B_1+20log(\frac{R_1}{R_2} )\\\\80=100+20log(\frac{5}{R_2} )\\\\-20=20log(\frac{5}{R_2} )\\\\log(\frac{5}{R_2} )=-1\\\\\frac{5}{R_2}=10^{-1}\\\\\frac{5}{R_2}=0.1\\\\R_2=5/0.1=50\ m[/tex]
a man weighing 490 n on earth weighs only 81.7 n on the moon. His mass on the moon is__kg. (Use g=9.8 m/s2
Answer:
m = 50 [kg]
Explanation:
In order to solve this problem we must be clear about the difference between weight and mass. Weight is the product of mass by the acceleration of the planet or the star. While the mass is always preserved it never changes regardless of where it is located.
So for the earth we have:
g = gravity acceleration = 9.8 [m/s^2]
m = mass [kg]
W = weigth = 490 [N]
therefore the mass will be:
m = W/g
m = 490/9.8
m = 50 [kg]
Now it is important to remember that the mass will be the same on the moon or on the earth, but the weight will be different, because the gravity acceleration of the moon is different from the gravity acceleration on earth
So the gravity on the moon is equal to:
81.7 = 50 * gm
gm = 1.634 [m/s^2]
A plastic block of dimensions 2.00 cm x 3.00 cm x 4.00 cm has a mass of 30.0 g. What is its density?
Answer:
1.25 g/cm^3
Explanation:
mass-30.0g
volume- 4cm×2cm×3cm=24cm^3
density?
*to find density
Density=Mass/Volume
=30÷24
=1.25g/cm^3
2. A bird flying horizontally at 10 m/s drops a branch. The bird is flying at an altitude of 20 m. Determine
the horizontal displacement it moves relative to where it was dropped.
Answer:
The horizontal displacement is 20 m.
Explanation:
Given that,
Velocity = 10 m/s
Height = 20 m
We need to calculate the time
Using equation of motion
[tex]s=ut+\dfrac{1}{2}gt^2[/tex]
Put the value into the formula
[tex]20=0+\dfrac{1}{2}\times9.8\times t^2[/tex]
[tex]t^2=\dfrac{20\times2}{9.8}[/tex]
[tex]t=\sqrt{\dfrac{20\times2}{9.8}}[/tex]
[tex]t=2.0\ sec[/tex]
We need to calculate the horizontal displacement
Using formula of horizontal displacement
[tex]\Delta x=v_{x}\times t[/tex]
Put the value into the formula
[tex]\Delta x=10\times2.0[/tex]
[tex]\Delta x=20\ m[/tex]
Hence, The horizontal displacement is 20 m.
Plates slide past one another at____.
A. Subduction zones
B. Transform boundaries
C. Convection currents
D. Divergent boundaries
Answer:
Transform Boundary
Explanation:
The just slide past each other
Answer:
Transform Boundaries
Explanation:
A cannonball is fired horizontally from a 10 m high cliff at 20 m/s. How long will the cannonball be in the air? How far away will the cannonball strike the ground?
Answe ¡Buenos días! –
#3 ¡Buenas tardes! –
#4 ¡Bienvenid
At which point on the image to the right would the ball have the greatest velocity if it moved from A to G.
please help me out.
A
B
C
D
E
F
G
Answer:
Total energy = Kinetic Energy + Potential Energy = Constant
Since the potential energy is lowest at point D the kinetic energy will be greatest at point D and the velocity will be the greatest.
SOH-CAH-TOA is used to solve for the ________
velocities in a full/angled projectile.
a. final (x and y)
b. overall
c. initial (x and y)
d. resultant
Answer:
c. initial (x and y)
Explanation:
When a projectile is launched at a velocity with a launch angle, to solve it, we must first resolve the initial velocity into the x and y components. To do this will mean we have to treat it like a triangle due to the launch angle and the direction of the projectile.
Therefore, we will have to make use of trigonometric ratios which is also known by the mnemonic "SOH CAH TOA"
Thus, this method resolves the initial x and y velocities.
give three factors which are responsible for the vanishing forest
Answer:
1. Huge wildfires
2. Deforestation
3. Reduced amount of aforestation, etc
The interaction between electrical energy and magnetism has been an important
topic in 20th century science, Which term describes this interaction?
Answer:
Maybe
Explanation:
I say maybe because it will help them still but not quite
Light of wavelength 580 nm falls on a slit that is 3.70×10−3mm wide. Part A Estimate how far the first brightest diffraction fringe is from the strong central maximum if the screen is 10.0 m away.
Answer:
Explanation:
wavelength λ = 580 x 10⁻⁹ m
slit width d = 3.7 x 10⁻⁶ m
distance of screen D = 10 m
distance of first bright fringe = 1.5 x λ D / d
= 1.5 x 580 x 10⁻⁹ x 10 / 3.7 x 10⁻⁶
= 2351.34 x 10⁻³ m
= 2351.34 mm .
Which famous Baroque period composer wrote 46 pieces of music while in jail?
Answer:
John Sebastian Bach
Answer:
Johann Sebastian Bach
Explanation:
please tell me if i am wrong! thank you!
If an object is moving with a constant velocity to the right, what direction is the net force.
Group of answer choices
A.To the right
B.To the left
C.Net force is 0
D.Not enough information
Answer:
At constant velocity, his weight equals the force of friction. In other words, there is no net force. If however, he loosens his grip and decreases the friction force, he will accelerate downward.
Explanation:
Which two types of energy does a book have as it falls to the floor
Answer:
kinetic and potential energy
Explanation:
Two boxes of masses 3M and 5M are attached by a massless rope. They are being pulled to the right with a constant force of P = 800 N, which allows them to just overcome static friction, with a μs= 0.70 between the floor and the boxes.
a. Find M.
b. Find the Tension in the rope between the two boxes.
Answer:
a) about 14.577 kg
b) 300 N
Explanation:
b) In order for the acceleration to be the same for each mass, the 800 N force must be divided between the boxes in proportion to their mass. That is, the net force on the 5M mass must be 5/8 of the total force, or 500 N. Then the tension in the rope is 800 N -500 N = 300 N, which is 3/8 of 800 N.
Tension: 300 N
__
a) The total mass is 8M, and the total normal force on the floor is ...
F = ma = (8M)(9.8 m/s^2)
The friction force is 0.7 times this, and is equal to the 800 N force pulling on the boxes.
800 N = (8M)(9.8 m/s^2)(0.7)
M = 800/(8·9.8·0.7) kg ≈ 14.577 kg
A 30%-efficient car engine accelerates the 1300 kg car from rest to 10 m/s . How much energy is transferred to the engine by burning gasoline
Answer:
The Energy transferred to the engine by burning gasoline = 216.67 KJ
Explanation:
The parameters given are:
The efficiency of the car engine, E = 30% = 0.3
Mass, m = 1300 kg
Initial velocity, u = 0, since the car is from rest
The final velocity, v = 10 m/s
Since the car was moving, we calculate its kinetic energy.
kinetic energy = ((1/2) (m) (v^2)
((1/2) (1300 kg) (10 m/s^2)
= 65,000 j
The Energy, Q transferred to the engine by burning gasoline in this case
= potential energy / The efficiency of the car engine, E
Q = 65,000 j / 0.3
= 216,666.66 J
Converting Joule to kilojoule
where 1KJ = 1000j
216,666.66 J = 216.67 KJ
If the body with a mass of 4kg is moved by a force of 20 N, what is the rate of its acceleration?
Answer:
The answer is 5 m/s²Explanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula
[tex]acceleration = \frac{force}{mass} \\[/tex]
From the question
force = 20 N
mass = 4 kg
We have
[tex]a = \frac{20}{4} \\ [/tex]
We have the final answer as
5 m/s²Hope this helps you
Open Box. Consider a hollow box with the top missing. The sides have negligible thickness and each has length L and mass m. (a) Find the x-coordinate of the center of mass.
Answer:
x_{cm} = L / 2
Explanation:
The center of mass is defined by
[tex]x_{cm}[/tex] = 1 / M ∑ m_{i} x_{i}
where M is the total mass of the system
in this case the system is continuous so, for which we use the density
ρ = dm / dx
dm = ρ dx
substituting
x_{cm} = 1 / M ∫ x ρ dx
x_{cm} = ρ / M ∫ x dx
we integrate and evaluate from x = 0 to x = L
x_{cm} = ρ / M (L² /2 -0)
we introduce the density which is constant
ρ = M / L
x_{cm} = 1 /M (M/L) L² / 2
x_{cm} = L / 2
A spring is stretched from rest and released. Which of the following describes the
frequency of the spring?
A:the speed of the spring as it passes through the equilibrium position
B: the number of times the spring moves up and down in 1 second
C:the time it takes the spring to compress and then expand once
D: the number of coils on the spring
Explanation:
you have given two questions which one to answer
Newton's first law states that objects do not change their motion unless acted upon by a net force. What does the word 'net' mean in this context?
A woven net, such as a fishing net or basketball net
B To catch or ensnare
C Remaining or left over after everything has been accounted for
D To cover, such as with mosquito netting