Forces Homework: Finding Work and Velocity

In summary, we have a body with a mass of 1kg at rest. When a force of 5N acts on it, the body displaces 4m with no friction. Using the formula Work = Force * Displacement, we find that the work done by the force is 20J. To find the velocity at the end of the displacement, we use the formula v^2 = v0^2 + 2ax, where a is the acceleration. Since we know the force and mass, we can find the acceleration to be 5m/s^2. However, we are missing the initial velocity and time. Using the formula a = (v1-v0)/t, we can rearrange to solve
  • #1
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Homework Statement


We have a body with mass=1kg and it's on rest. When a force of 5N acts on it , the body displaces 4m. Assume no friction
Find:
a)The work that force did
b)Velocity at the end of the distance(displace)
a)
##Work=Force * Displacement = 5N*4m = 20J##
##A=Fd=(5N)(4m)=20J##
b)
Uhm,
##F=\frac{mv}{t}##, i have no time given. My teacher said this has a solution, it's not wrong. I'm stuck here




The Attempt at a Solution


a)
##Work=Force * Displacement = 5N*4m = 20J##
##A=Fd=(5N)(4m)=20J##
b)
Uhm,
##F=\frac{mv}{t}##, i have no time given. My teacher said this has a solution, it's not wrong. I'm stuck here
 
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  • #2
Look for a kinematic formula that relates velocity, acceleration, and distance, since those are the things you have to work with.
 
  • #3
Ehm, maybe that would be:
##a=F/m##
##a=5N/1kg=5m/s^2##
##a=\frac{Δ v}{Δ t}##
##5m/s^2=\frac{v_1-0}{t}##
I have no v_1(which i have to find) and I have no time..
If so, would that be
##v^2=v_0^2+2ax## which gives us
##v^2=0m^2/s^2+2(5m/s^2)(4m)##
##v^2=40m^2/s^2##
##v=\sqrt{40}=6.324555320336759m/s##
 
  • #4
That works!
 
  • #5
thanks!
 

FAQ: Forces Homework: Finding Work and Velocity

What is work in relation to forces and how is it calculated?

Work is the measure of the amount of energy required to move an object a certain distance against a force. It is calculated by multiplying the force applied to an object by the distance the object moves in the direction of the force. The formula for work is W = F * d, where W is work, F is force, and d is distance.

How do you calculate the velocity of an object using force and work?

Velocity is a measure of an object's speed and direction of motion. It can be calculated by dividing the work done on the object by the force applied to the object. The formula for velocity is v = W / F, where v is velocity, W is work, and F is force.

How can you use work and velocity to determine the net force acting on an object?

According to Newton's Second Law of Motion, the net force acting on an object is equal to the mass of the object multiplied by its acceleration. Velocity is directly related to acceleration, so by using the formula for velocity (v = W / F), you can calculate the net force on an object by multiplying the object's mass by its velocity.

What is the difference between work and power?

While work measures the amount of energy required to move an object, power measures how quickly work is done. Power is calculated by dividing the work done by the amount of time it takes to do the work. The formula for power is P = W / t, where P is power, W is work, and t is time.

How can you use work and velocity to determine the kinetic energy of an object?

Kinetic energy is the energy an object possesses due to its motion. It can be calculated by multiplying the mass of the object by its velocity squared and dividing by two. The formula for kinetic energy is KE = 1/2 * m * v^2, where KE is kinetic energy, m is mass, and v is velocity.

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