Calculate Momentum & Energy for 15 Metric Ton Train

In summary: Glad I could help!In summary, the 15 metric ton train moves at 70 m/s and needs to travel at 350 m/s to have five times its original momentum. To have a momentum of 5 × 105 kg · m/s, the train needs to travel at 33.3 m/s. To slow the train down to 10 m/s while maintaining the same momentum, an additional 35,000 kg must be added to the original mass of 15,000 kg.
  • #1
Ronaldo21
30
0
part (1 of 3 ). A 15 metric ton train moves toward the south at 70 m/s.
At what speed must it travel to have five times its original momentum? A metric ton
is 1000 kg.
Answer in units of m/s.

and

Part (2 of 3 ). At what speed must it travel to have a momentum of 5 × 105 kg · m/s?
Answer in units of m/s.

and

Part (3 of 3). If there were a speed limit for this train as it traveled through a city, but not a weight limit, what mass must be added to the train to slow it down to 10 m/s while at the same time keeping the momentum the same as in the second part?
Answer in units of kg.

THANK YOU!
 
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  • #2
Part 1: p = mv

So pi= 15000kg*70m/s = 1,005,000 Ns

pf = 5*pi = 5,250,000 Ns

Since we can't change the train's mass, we have to change its speed: 5,250,000 = 15000*v, v= 350 m/s
 
  • #3
Part 2: 5 x 10^5kg*m/s

So if p = mv, then 5x10^5kg*m/s = 15000*v

so v = 33.3 m/s
 
  • #4
Part 3:
so
p = 5 x 10^5 Ns
v = 10 m/s

p = mv, m = p/v; m = 50000kg final weight. Train starts out at 15000kg, so you must add 35000kg to have a total weight of 50000kg
 
  • #5
wow! thank you soo much! this makes so much more sense now!
 
  • #6
sure thing!
 

Related to Calculate Momentum & Energy for 15 Metric Ton Train

What is momentum?

Momentum is a measure of an object's motion, calculated by multiplying its mass by its velocity.

How do you calculate momentum?

To calculate momentum, you multiply an object's mass (in kilograms) by its velocity (in meters per second). The formula for momentum is: momentum = mass x velocity.

What is energy?

Energy is the ability to do work or cause change. It comes in different forms, such as kinetic energy (the energy of motion) and potential energy (stored energy).

How do you calculate kinetic energy?

Kinetic energy is calculated by multiplying an object's mass by its velocity squared, and then dividing by 2. The formula for kinetic energy is: KE = 1/2 x mass x velocity^2.

What is the momentum and kinetic energy of a 15 metric ton train moving at 30 meters per second?

The momentum of the train would be 450,000 kg*m/s (15 metric tons x 30 m/s), and the kinetic energy would be 202,500,000 joules (1/2 x 15 metric tons x 30 m/s^2).

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