# Need help on the Law of Momentum Conservation?!?

*label*Science

*timer*Asked: Mar 29th, 2015

**Question description**

**Part 2**: Complete the following math problems by using the Law of
Momentum Conservation.

Formulas:

**i.** Momentum = (mass) *
(velocity)**
ii.** Impulse = (Applied force) * (time)

*Impulse = Change in Momentum*

__and__**Applied Force = (Change in Momentum) / (time)**

iii.

iii.

**For multiple objects: Total Momentum of everything before interaction = Total Momentum of everything after**

iv.

iv.

6. A car of mass 1100kg moves at 24 m/s. What is the braking force needed to bring the car to a halt in 2.0 seconds? (Use i and iii)

7. What is the force on a 0.025 kg egg from a bed sheet as the egg hits the sheet at 4.0 m/s and takes 0.2 seconds to stop? (Use i and iii)

8. A 8.0 kg shell leaves a 2.0 x 10^{3} kg cannon, at a speed of 4.0
x 10^{2} m/s. What is the recoil speed of the cannon? (Use i and iv)

9. A 1.0 kg dart moving horizontally at 10.0 m/s makes impact and sticks to a piece of wood with a mass of 9.0 kg, which then slides across a friction free surface. What is the speed of the wood and dart after the collision? (Use i and iv)

10. A 10,000-kg train car coasting at 10 m/s collides with a 2000-kg automobile coasting at 30 m/s in the opposite direction. If the stick together after the impact how fast and in what direction will they be moving? (Use i and iv)