Calculating Velocity from Conservation of Momentum: A Science Tutorial

  • Thread starter AndrewMorris
  • Start date
In summary, the concept of "Man jumps on moving wagon" involves an individual attempting to jump onto a wagon that is already in motion. The speed of the wagon plays a crucial role in the success of the jump, as a faster moving wagon may make it more difficult to time the jump correctly and increase the risk of injury. There are several potential risks involved in attempting to jump onto a moving wagon, including falling, getting caught in the wheels or undercarriage, and losing balance. To minimize these risks, it is essential to carefully assess the speed and direction of the wagon and have proper training and physical ability. However, jumping onto a moving wagon is not a recommended activity as it carries a high risk of injury and should only be attempted
  • #1
AndrewMorris
4
1
Homework Statement
My daughter was asked this question:
A person of mass 60 kg running at 8 m/s reaches a wagon of mass 80 kg going at 2 m/s and jumps onto it. Calculate the velocity of the wagon immediately after the person jumps on.
Relevant Equations
total momentum before impact = total momentum after impact
Using conservation of momentum I would say (60 x 8) + (80 x 2) = (60 + 80) v
so v = 400/140 = 2.86 m/s.
However, this is not one of the multiple choice responses. What am I doing wrong?
 
Physics news on Phys.org
  • #2
Setup looks right. But check the number 400.
 
  • Like
Likes Orodruin
  • #3
Apart from that, consider using symbolic calculations and only insert your numbers at the end. It often avoids this kind of mistakes. Or at least use units throughout.
 
  • Like
Likes TSny
  • #4
oh man, I used to be good at maths, honest. Thanks :-)
 
  • #5
AndrewMorris said:
oh man, I used to be good at maths, honest. Thanks :-)
It was just a careless error. Happens to us all :oldsmile:
 

FAQ: Calculating Velocity from Conservation of Momentum: A Science Tutorial

What is the scientific explanation for why a man can jump on a moving wagon?

The scientific explanation for why a man can jump on a moving wagon is due to the principle of inertia. An object in motion will continue to stay in motion unless acted upon by an external force. In this case, the man's body is in motion along with the wagon, and his jump provides the external force needed to change his direction and land on the wagon.

Is it safe for a man to jump on a moving wagon?

It is not recommended for a man to jump on a moving wagon as it can be dangerous. There is a risk of falling and getting injured, especially if the man does not have proper balance or timing. It is always best to avoid such stunts and prioritize safety.

What factors can affect a man's ability to successfully jump on a moving wagon?

Several factors can affect a man's ability to successfully jump on a moving wagon, including their physical strength, coordination, balance, and timing. The speed and stability of the wagon, as well as the surface it is moving on, can also play a role.

Can anyone jump on a moving wagon or does it require special skills?

Jumping on a moving wagon requires a certain level of skill, coordination, and physical ability. It is not recommended for everyone to attempt this stunt, as it can be dangerous. It is best to leave it to trained professionals who have the necessary skills and experience.

What other scientific principles are involved in a man jumping on a moving wagon?

In addition to the principle of inertia, other scientific principles involved in a man jumping on a moving wagon include gravity, force, and momentum. These principles all work together to determine the trajectory and outcome of the jump.

Back
Top