Question

Please help 50 points

Answer 1

Answer:

3a 0.7m/s

3b partially inelastic

4a 8.33 m/s

4b completely inelastic

5. puck: 10.59 m/s octopus: 10.59m/s

6. car: 117.44 m/s truck: 17.44m/s

7a - 1 m/s , the red cart travels to the left

7b) elastic

Explanation:

For all these questions, you have find momentum (P=mv) always remember initial P is always equal to final P

3.

Initial P:

mass of first ball x velocity of first ball + mass of second ball x velocity of second ball

0.5*3.5 + 0.5*0 = 1.75 kg.m/s

final P: also 1.75Kg.m/s

let x be the velocity for first ball

0.5*2.8+0.5*x=1.75

0.5x=1.75-1.4

     x=0.35/0.5

      x=0.7m/s

b) collision is elastic when KEi = KEf, so calculate and see if that's true

using 1/2mv² we know KEi does not equal to KEf

so the collision is partially inelastic, partially because the ball did not stick together

4.

Initial P:

2575*11 + 825*0 = 28,325 kg.m/s

final P: also 28,325 Kg.m/s

let x be the velocity for both vehicles

(2575+825)x=28325

                   x=28325/3400

                    x=8.33 m/s

b) collision is elastic when KEi = KEf, so calculate and see if that's true

using 1/2mv² we know KEi does not equal to KEf

so the collision is completely inelastic, completely because the vechicles slides off together

5

Initial P:

0.115*35 + 0.265*0 = 4.025 kg.m/s

final P: also 4.025Kg.m/s

since they slides off together, the velocity will be the same, so let x be the velocity for the puck and octopus,

(0.115+0.265)x=4.025

                     x=4.025/0.38

                     x=10.59

6. Initial P:

565*25+785*12 = 23,545 kg.m/s

final P: also 23,545 Kg.m/s

since they slides off together, the velocity will be the same, so let x be the velocity for the car and truck,

(565+785)x=23545

                 x=23545/1350

                 x=17.44

7.

Initial P:

0.25*2 + 0.75*0 = 0.5 kg.m/s

final P: also 0.5 Kg.m/s

let x be the velocity for red cart

0.75*1+0.25*x=0.5

0.25x=0.5-0.75

     x=-0.25/0.25

      x=-1m/s

b) collision is elastic when KEi = KEf, so calculate and see if that's true

using 1/2mv² we know KEi equals to KEf

so the collision is elastic