Question

A cart of mass m moving right at speed v with respect to the track collides with a cart of mass 0.7m moving left.

Answer 1

Answer:

10/7 * V.

Explanation:

Momentum = mass * velocity

Given:

Mass of cart 1 = M1

Mass of cart 2 = M2

= 0.7M1

Initial velocity of cart 1 = Vi1

= V

Initial velocity of cart 2 = Vi2

Final velocity = V

= 0

Initial momentum of cart 1 + initial momentum of cart 2 = total mass of both cart * velocity

M1 * Vi1 + M2 * Vi2 = (M1 + M2) * V

= M * V - (0.7M * Vi2) = (M + 0.7M) * 0

= MV - 0.7M * Vi2 = 0

Vi2 = 10/7 * V.

Answer 2

Answer:

10v / 7

Explanation:

Using the conservation law of momentum

m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂

m v - 0.7 m v₁ =  ( 0.7 m + m) 0 m/s since the cart stuck together after collision. taken right to be positive and left to be negative

m v - 0.7 m v₁ = 0

- 0.7 m v₁ = -m v

v₁ = -m v / - 0.7 m = 10v / 7