"Collision Homework: Find Mass of Cart & Impact Force

In summary, the problem involves a cart with a velocity of 2 m/s and a child with a mass of 2 kg running at 2 m/s in the opposite direction. The child jumps onto the cart and the cart's velocity is reduced to 1 m/s. The first part of the problem involves finding the mass of the cart, which is determined to be 14.64 kg using the conservation of momentum equation. The second part involves finding the impact force perpendicular to the tracks, but there is not enough information given to solve for this.
  • #1
mmoadi
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Homework Statement



A cart is driving on straight tracks with a velocity of 2 m/s. In the opposite direction, with an angle of 60º according to the tracks, a child with a mass of 2 kg is running with a velocity of 2m/s, he jumps on the cart and stays there.
- Find the mass of the cart, if its velocity is reduced to 1 m/s when the child jumps onto it.
- What is the impact force perpendicular to the tracks?

http://www.slide.com/s/QOXg7ix_pD-d7WoZA5-k0knIny1R-ZsX?referrer=hlnk [Broken]

Homework Equations



p= mv
F= ma

The Attempt at a Solution



First part: Find the mass of the cart, if its velocity is reduced to 1 m/s when the child jumps onto it.

Conservation of the moment:

m(2)= 20 kg, v(1-initial)= v(2-initial)= 2 m/s, v(3)= 1 m/s, θ= 60º

m(1)v(1) + m(2)v(2)sinθ= (m(1) + m(2))v(3)
2m(1) + 34.64= m(1) + 20
m(1)= 14.64 kg

Are my calculations correct?

Second part: What is the impact force perpendicular to the tracks?

For this part, I know that the formula for impact force is F(impact)=m(Δv/Δt), but I don't know which mass to use and I don't have the time (t).
Any hint what I should do, or is there another equation to find the impact force without knowing the time (t)?

Thank you for helping!
 
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  • #2


Can someone, please, take a look at this problem!
Thank you!
 
  • #3


I would first confirm that your calculations for the mass of the cart are correct. It is always important to double check your work and ensure that your calculations make sense in the context of the problem.

For the second part, you are correct that you do not have enough information to calculate the impact force using the equation F = m(Δv/Δt). However, you can use the conservation of momentum principle to find the impact force. This principle states that the total momentum before and after a collision must be equal.

Using this principle, you can set up an equation with the momentum before the collision (m(1)v(1)) equal to the momentum after the collision ((m(1) + m(2))v(3)). You can then solve for the impact force (F) by rearranging the equation to F = (m(1) + m(2))v(3) - m(1)v(1).

Hope this helps!
 

What is the purpose of "Collision Homework: Find Mass of Cart & Impact Force"?

The purpose of this homework assignment is to practice applying the principles of collisions, specifically finding the mass of a cart and calculating the impact force.

What equipment is needed to complete this homework?

To complete this homework, you will need a cart, a track, a force sensor, and a computer with data analysis software.

How do I find the mass of the cart?

To find the mass of the cart, you will need to set up the track and cart, attach the force sensor, and then record the data of the cart's motion during a collision. Then, using the equations for collisions, you can calculate the mass of the cart.

What is impact force and how is it calculated?

Impact force is the force exerted on an object during a collision. It is calculated by dividing the change in momentum by the time of the collision. In this homework, you will use the data collected from the force sensor to calculate the impact force of the cart during collision.

Why is it important to calculate the mass of the cart and the impact force?

Calculating the mass of the cart and the impact force allows us to better understand the dynamics of collisions and the effects of forces on objects. It also allows us to make predictions and analyze the safety and efficiency of different scenarios, such as car crashes or sports collisions.

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