You need to know the coefficient of static friction between a wooden object and a wooden surface. I'll denote it with µ. If you're given a specific value you should obviously use that.
By Newton's second law, the horizontal and vertical net forces are
• net horizontal:
∑ F = p - f = 0
• net vertical:
∑ F = n - w = 0
where
p = magnitude of the pushing force
f = mag. of friction
n = mag. of the normal force
w = weight of the crate
The second equation gives
n = w = (5 kg) (9.8 m/s²) = 49 N
Friction is proportional to the normal force by a factor of µ, so
f = µ (49 N) = 49µ N
To overcome static friction, the push has to exceed this in magnitude, so that
p > 49µ N
For instance, if p = 0.25, then p would need to greater than 12.25 N. (This example isn't particularly helpful, though, since both possibly correct options are larger than 12.25 N...)
stopping potential becomes more and more negative why
Answer:
stopping potential is the negative potential applied to the circuit to stop the moving electrons so as to stop the flow of current
for high current high negative potential is applied
A space probe is sent to an alien planet and conducts an experiment in order to determine the acceleration due to gravity on the planet. It produces the following table
Object Rock Grain of sand Metal bolt
Mass 20 grams 0.8 grams 79 grams
Recorded force of gravity :0.1224 N 0.00501 N 0.4871 N
Given this data, which of the following the closest approximation of the acceleration due to gravity on this planet
a
3.8 m/s^2
b
4.0 m/s^2
c
9.9 m/s^2
d
6.1 m/s^2
Answer: D. 6.1 m/s^2
Explanation:
PLEASE HELP ME
1) If a bus travelling at 20 m/s is subject to a steady deceleration of 5 m/s2, how long will it
take to come to rest?
Answer:
Bus will take 4 seconds before it comes to rest.
Explanation:
Initial Velocity of bus = u = 20 ms⁻¹
Final Velocity of bus = v = 0 ms⁻¹
Deceleration of bus = a = -5 ms⁻²
Time taken by bus before it comes to rest = t = ?
Using the equation formula
a = (v - u)/t
-5 = (0 - 20) / (t)
t = -20/-5
t = 4 sec
Therefore, Bus will take 4 seconds before it comes to rest.
what is force?answer in one line.
A 430.0 g mass is being pushed by a 1.1 N net force. What is the acceleration?
Answer:
[tex]a = 2.56\ m/s^2[/tex]
Explanation:
Mechanical Force
According to the second Newton's law, the net force exerted by an external agent on an object of mass m is:
F = m.a
Where a is the acceleration of the object.
The object has a mass of m=430 g = 0.43 Kg and is pushed by a net force of F=1.1 N. To calculate the acceleration, we solve for a:
[tex]\displaystyle a=\frac{F}{m}[/tex]
[tex]\displaystyle a=\frac{1.1}{0.43}[/tex]
[tex]\mathbf{a = 2.56\ m/s^2}[/tex]
True or False: Solids always have a higher density than liquids and gases.
Answer:
TRUE THE ANSWER IS TRUE
A 52.0-kg woman wearing high-heeled shoes is invited into a home in which the kitchen has vinyl floor covering. The heel on each shoe is circular and has a radius of 0.600 cm. If the woman balances on one heel, what pressure does she exert on the floor?
Answer:
4.5 × 10^6 Nm
Explanation:
Given that a 52.0-kg woman wearing high-heeled shoes is invited into a home in which the kitchen has vinyl floor covering. The heel on each shoe is circular and has a radius of 0.600 cm. If the woman balances on one heel, what pressure does she exert on the floor?
Let's first calculate the area covered by the heel shoe by using the area of a circle.
Convert cm to m
0.6 / 100 = 0.006
A = πr^2
A = 22/7 × 0.006^2
A = 1.131 × 10^-4 m^2
The force exerted by the woman = mg
Force exerted = 52 × 9.8
Force exerted = 509.6 N
Pressure = force / Area
Pressure = 509.6 / 1.131 × 10^-4
Pressure = 4505853.3 N/m
Therefore, she exerts pressure of 4.5 × 10^6 Nm approximately on the floor.
2. 290 grams of water is to be heated from 24.0% to 100.0°C to make a cup of
tem, how much heat must be added? The specific heat of water is 4.18 J/g•C
Answer:
92127.2 j
Explanation:
Given that :
Mass of water = 290 g
Specific heat of water (C) = 4.18 j/g.C
Initial Temperature (t1) = 24°C
Final temperature (t2) = 100°C
Using the relation :
Q = mCdt
dt = change in temperature =( 100 - 24)° = 76°C
Q = quantity of heat ; C = specific heat capacity;
m = mass of substance
Q = 290 g * 4.18 j/g.C * 76°C
Q = 92127.2 j
What could you do to decrease the rate at which salt dissolves in water?
Add more salt.
Stir the mixture.
Use cold water.
Use hot water.
Answer:
use hot water
Explanation:
hot water helps dissolve things faster
ASTRONOMY
Match the following phases of stellar evolution to its characteristics.
*please help me thx*
Answer:
1. Brown dwarf.
2. Red giant.
3. Black dwarf.
4. White dwarf.
5. Black hole.
Explanation:
A star is a giant astronomical or celestial object that is comprised of a luminous sphere of plasma, binded together by its own gravitational force.
Basically, stars are typically made up of two (2) main hot gas, Hydrogen (H) and Helium (He).
Some of the examples of stars are; Canopus, Sun (closest to the Earth), Betelgeus, Antares, Vega etc.
1. Brown dwarf: does not undergo hydrogen fusion.
2. Red giant: has an outer shell of burning hydrogen and a core of helium.
3. Black dwarf: a white dwarf that has lost all its energy.
4. White dwarf: has a core of carbon that is not massive enough to fuse. A white dwarf also known as degenerate dwarf is a star or an electron degenerate matter and is as massive as the Sun but only about as large in size as planet Earth. Also, the maximum mass of a white dwarf is about 1.4 times the mass of the Sun.
5. Black hole: formed from the collapse of a white dwarf beyond 1.5 solar masses.
Answer:
other person is correct!!!
Explanation:
got 100 on test
You want to move a spacecraft that is in 300 km circular orbit around Venus into another circular orbit around Venus of 600 km. Explain how you would accomplish this. Solve for the velocities that need to be applied.
Answer:
The final velocity will be half of the initial velocity of the spacecraft.
Explanation:
Angular momentum is conserved for the circular force motion and central force motion.
Considering
L = MVR = Constant
Where
M = Mass of the object
V = Velocity of the object
r = radius of circle
We know that
V = [tex]\frac{1}{R}[/tex]
So,
[tex]\frac{V_{2} }{V_{1} }[/tex] = [tex]\frac{R_{1} }{R_{2} }[/tex]
As per the given data
[tex]R_{1}[/tex] = Initial Radius = 300 km
[tex]R_{2}[/tex] = Final Radius = 600 km
[tex]V_{1}[/tex] = Initial Velocity =
[tex]V_{2}[/tex] = Final Velocity =
Placing values in the formula
[tex]\frac{V_{2} }{V_{1} }[/tex] = [tex]\frac{300 km}{600 km }[/tex]
[tex]\frac{V_{2} }{V_{1} }[/tex] = [tex]\frac{1}{2}[/tex]
[tex]{V_{2}[/tex] = [tex]\frac{1}{2} V_{1}[/tex]
Hence, The final velocity will half of the initial velocity of the spacecraft.
What happens when someone lets go of the button on an electric doorbell?
The electromagnet gets stronger.
The circuit is broken and the electromagnet turns off.
The current moving through the circuit changes direction.
The metal striker hits the bell.
Answer:
The current moving through tha circuit changes direction.
Explanation:
hope this helps
The electromagnet is activated. It causes a buzzer to go off. The hammer strikes the bars which creates sound. When you let go, it will stop making a sound by the circuit stop flowing.
What is electromagnet ?"Electromagnet, device consisting of a core of magnetic material surrounded by a coil through which an electric current is passed to magnetize the core. An electromagnet is used wherever controllable magnets are required, as in contrivances in which the magnetic flux is to be varied, reversed, or switched on and off."
What is Circuit ?"A circuit is a complete circular path that electricity flows through. A simple circuit consists of a current source, conductors and a load. The term circuit can be used in a general sense to refer to any fixed path that electricity, data or a signal can travel through."
Know more about electromagnet here
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These steps are involved in the production of work by a four-stroke heat engine. Place the steps in the correct order. Piston moves up, compressing gas and causing gas to increase its temperature: Piston moves up, pushing burned gases through exhaust valve: 1 Spark plug fires, causing combustion as gas is still compressed; increase in energy from combustion pushes piston down: Piston moves down, allowing fuel-air mixture to enter intake valve:
Answer:
correct order 2,4,3,1
Explanation: correct on edge
An insulating rod is bent into the shape of a quarter-circle having total charge Q distributed uniformly over its length. At the origin, the magnitude of the total electric field due to this charge configuration is E0 and the potential is V0. A second insulating rod is added to the fourth quadrant to complete a semi-circle. This second quarter-circle has charge -Q uniformly distributed. In terms of E0 and V0, determine the total electric field vector and the total potential at the origin due to the semi-circle of charge.
Answer:
E = - 2*E₀*sinθ*i
V = V = 2*E₀*sinθ /r
Explanation:
First situation: a quarter-circle rod produces at the origin
E₀ and V₀
We know that E = K * Q/r and
E = E₀ Q = L*λ Q = 1/4 * 2*π*r*λ Q = (1/2)*π*r*λ
where:
r is the radius of the circle which at the same time is the distance between the rod quarter of the circle and the origin.
λ is the longitudinal density of charge, and
k = 1/4*π*ε₀
Then E₀ = (1/2)* k*π*λ and V₀ = - E₀/Q V₀ = - E₀/r
E₀ = E₀ₓ + E₀y E₀ₓ = E₀*cosθ E₀y = - E₀*sinθ
θ the angle between E₀ and the x-axis
Second situation half of a circle ( first quarter +Q and fourth -Q )
In that configuration, the components in the x-axis cancel each other ( by symmetry) and the y-axis components of +Q and -Q are to be added then
E = Eₓ + Ey but by inspection we find Eₓ = 0 ( the components of the
the electric field produced of the two quarters canceled each other)
and we have to add the two identical y-axis components of the two quarters therefore
E = 2*E₀y
each component of E₀y = - E₀*sinθ
Then the new electric field becomes
E = - 2*E₀*sinθ*i
The new V = - (- 2*E₀*sinθ /r)
V = 2*E₀*sinθ /r
(Note remember that V is a scalar )
23 POINTS!! will get brainiest
What is the relationship between temperature range and proximity to the coast?
Answer:I think it’s because both can provide heat and cold
Explanation:
Two planes of charge with no thickness, A and B, are parallel and vertical. The electric field in region I to the left of plane A has magnitude 3σ/2????0 and points to the left. The electric field in the region to the right of B has magnitude 3σ/2????0 and points to the right. The electric field in the region between the two planes has magnitude σ/2????0 and points to the right. The surface charge density on planes A and B respectively is
Answer:
The surface charge density on planes A and B respectively is
[tex]\sigma__{A}} } = 2\sigma[/tex]
and
[tex]\sigma__{B}} = \sigma[/tex]
Explanation:
From the question we are told that
The electric field in region to the left of A is [tex]E_i = \frac{3 \sigma}{2 \epsilon_o}[/tex]
The direction of the electric field is left
The electric field in the region to the right of B is [tex]E_f = \frac{3 \sigma}{2 \epsilon_o}[/tex]
The direction of the electric field is right
The electric field in the region between the two planes is [tex]E_m = \frac{\sigma }{2 \epsilon_o }[/tex]
The direction of the electric field is right
Let the surface charge density on planes A and B be represented as [tex]\sigma__{A}} \ \ and \ \ \sigma__{B}} \ \ \ respectively[/tex]
From the question we see that
[tex]E_i = E_f[/tex]
Generally the electric to the right and to the left is due to the combined electric field generated by plane A and B so
[tex]E_i = E_f = \frac{3\sigma }{2\epsilon} = \frac{\sigma_A }{ 2 \epsilon_o } + \frac{\sigma_B }{ 2 \epsilon_o }[/tex]
=> [tex]\sigma__{A}} + \sigma__{B}} = 3 \sigma -- -(1)[/tex]
Generally the electric field at the middle of the plane A and B is due to the diffencence in electric field generated by plane A and B
i.e
[tex]\frac{\sigma }{2 \epsilon_o } = \frac{\sigma_A }{ 2 \epsilon_o } - \frac{\sigma_B }{ 2 \epsilon_o }[/tex]
=> [tex]\sigma__{A}} - \sigma__{B}} = \sigma[/tex]
=> [tex]\sigma__{A}} } = \sigma + \sigma__{B}[/tex]
From equation 1
[tex]\sigma + \sigma__{B}}+ \sigma__{B}} = 3 \sigma[/tex]
=> [tex]\sigma__{B}} = \sigma[/tex]
So
[tex]\sigma__{A}} } = \sigma + \sigma[/tex]
=> [tex]\sigma__{A}} } = 2\sigma[/tex]
which statement about force is incorrect
Answer:
What are the options?
Explanation:
A small hole P is made in a piece of cardboard. The hole is illuminated by a torch as shown in Fig. 16.3. The pencil of light coming out of the hole falls on a mirror.
5th question
Answer:
According to law of reflection i know in case of plane mirror the angle of reflection is equal to the angle of incidence. So,if you placed the eye on point A the hole can be seen.
Explanation:
please answer True or false
In two square the server earns a point when the opponent catches the ball.
The spiral spring showed are identical. Each spring has a spring constant K =100N/m determine the total extension caused by the 150N weight
1 spring k=100
2 springs k =200
f=kx
then k=f/x
200=150/x
x=200/150
x=4/3
Explanation:
need thanks ..................
The total extension caused by the 150N weight is 1.5 m
Data obtained from the question Spring constant (K) = 100 N/mForce (F) = 150 NExtention (e) =? How to determine the extensionFrom Hooke's law,
Force (F) = spring constant (K) × extention (e)
F = Ke
150 = 100 × e
Divide both side by 100
e = 150 / 100
e = 1.5 m
Therefore, the total extention caused by the weight is 1.5 m
Learn more about spring constant:
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1. What is the total distance traveled?
A 3.0m
B 4.0m
C 5.0m
D 6.0m
Answer:
c
Explanation:
When an object falls, it is reacting to the force of gravity. true or false
Answer:
The answer is true, as gravity affects everything.
A force of 22.7 N stretches an elastic band at room temperature. The rate at which its entropy changes as it stretches is about _____ J/Km. Round your answer to 3 decimal places.
Answer:
The value is [tex]\frac{\Delta S }{ L} = - 0.0721 \ J / km[/tex]
Explanation:
From the question we are told that
The force is [tex]F = 22.7 \ N[/tex]
The value of room temperature is [tex]T = 298 \ K[/tex]
Generally the rate at which its entropy changes as it stretches is mathematically represented as
[tex]\frac{\Delta S }{ L} = - \frac{F}{T}[/tex]
=> [tex]\frac{\Delta S }{ L} = - \frac{21.5}{ 298 }[/tex]
=> [tex]\frac{\Delta S }{ L} = - 0.0721 \ J / km[/tex]
_________ is the distance an object travels per unit of time.
(5 Points)
speed
displacement
velocity
rate
Explanation:
Speed is the distance an object travel per unit of time
A football quarterback throws a football for a long pass. While in the motion of throwing, the quarterback moves the ball , starting from rest, and completes the motion in . Assuming the acceleration is constant, what force does the quarterback apply to the ball during the pass
This question is incomplete, the complete question is;
A football quarterback throws a 0.408 kg football for a long pass. While in the motion of throwing, the quarterback moves the ball 1.909 m, starting from rest, and completes the motion in 0.439 s. Assuming the acceleration is constant, what force does the quarterback apply to the ball during the pass ;
a) F_throw = 8.083 N
b) F_throw = 9.181 N
c) F_throw = 2.284 N
d) F_throw = 16.014 N
e) None of these is correct
Answer:
the quarterback applied a force of 8.083 N to the ball during the pass
so Option a) F_throw = 8.083 N is the correct answer
Explanation:
Given that;
m = 0.408 kg
d = 1.909 m
u = 0 { from rest}
t = 0.439 s
Now using Kinetic equation
d = ut + 1/2 at²
we substitute
1.909 = (0 × 0.439) + 1/2 a(0.439)²
1.909 = 0 + 0.09636a
1.909 = 0.09636a
a = 1.909 / 0.09636
a = 19.8111 m/s²
Now force applied will be;
F = ma
we substitute
F = 0.408 × 19.8111
F = 8.0828 ≈ 8.083 N
Therefore the quarterback applied a force of 8.083 N to the ball during the pass
so Option a) F_throw = 8.083 N is the correct answer
Do clouds have respiration
Answer:
yes it also does have but not in the exact form but it does 30 percent of respiration to produce rain
the maximum normal force a pilot can withstand is about eight times his weight. What is the maximum radius of curvature that a jet planes pilot, pulling out of a vertical dive
Complete Question
the maximum force a pilot can stand is about seven times his weight. what is the minimum radius of curvature that a jet plane's pilot, pulling out of a vertical dive, can tolerate at a speed of 250m/s?
Answer:
The value is [tex]r = \frac{250^2 }{6 * 9.8 }[/tex]
Explanation:
From the question we are told that
The weight of the pilot is [tex]W = mg[/tex]
The maximum force a pilot can withstand is [tex]F_{max} = 7 W = 7 (mg)[/tex]
The speed is [tex]v = 250 \ m/s[/tex]
Generally the centripetal force acting on the pilot is equal to the net force acting on the pilot i.e
[tex]F_c = F_{max} - mg[/tex]
Here N is the normal force acting on the pilot
Now
[tex]F_c = \frac{m v^2 }{r}[/tex]
So
[tex]\frac{m v^2 }{r} = 7(mg) - mg[/tex]
=> [tex]r = \frac{v^2 }{6g}[/tex]
=> [tex]r = \frac{250^2 }{6 * 9.8 }[/tex]
=> [tex]r = 1063 \ m[/tex]
A television camera is positioned 4 km from the base of a rocket launching pad. In order to keep the rocket in focus as it takes off, the camera must be programmed with the distance to the rocket and how that distance is changing. If we assume that the rocket rises vertically at a speed of 200 km/hr, how fast is the distance from the camera to the rocket changing when the rocket has risen 3 km
Answer:
120 km/hr
Explanation:
Let D be the distance between the rocket and the camera as the rocket is moving upwards. Let d be the distance the rocket moves and L be the distance between the camera and the base of the rocket = 4 km.
Now, at any instant, D² = d² + L²
= d² + 4²
= d² + 16 since the three distances form a right-angled triangle with the distance between the rocket and the camera as the rocket is moving upwards as the hypotenuse side.
differentiating the expression to find the rate of change of D with respect to time, dD/dt ,we have
d(D²)/dt = d(d² + 16)/dt
2DdD/dt = 2d[d(d)/dt]
dD/dt = 2d[d(d)/dt] ÷ 2D
Now d(d)/dt = vertical speed of rocket = 200 km/hr
dD/dt = 200d/D [D = √(d² + 16)]
dD/dt = 200d/[√d² + 16]
Now substituting d = 3 km, the distance the rocket has risen into the equation, we have
dD/dt = 200(3)/[√(3² + 16)]
dD/dt = 600/[√(9 + 16)]
dD/dt = 600/√25
dD/dt = 600/5
dD/dt = 120 km/hr
So, the speed at which the distance from the camera to the rocket changing when the rocket has risen 3 km is 120 km/hr.
When landing from a jump, a basketball player of mass 82 kg has a velocity of 1.2 m/s right before they hit the ground. The player then lands on the floor with their feet and is quickly brought to a stop. If the the floor deforms by 0.025 m while the player lands on it, what was the average force under the player's feet during the landing
Answer:
2361.6N
Explanation:
Mass of player = 82kg
Velocity = 1.2m/s
Kinetic energy of player:
= 1/2mv²
= 1/2*82*1.2²
= 41x1.44
= 59.04J
Final kinetic energy = 0
Change in kinetic energy
|∆k| = |0-59.04|
= 59.04
Workdone by the feet = fd
d = 0.025
Fd = 59.04
F = 59.04/0.025
= 2361.6N
This is his average force.
A woman exerts a horizontal force of 3 pounds on a box as she pushes it up a ramp that is 10 feet long and inclined at an angle of 30 degrees above the horizontal. Find the work done on the box.
Answer: 67 how much candy does nick have
Explanation: