Question

Can someone help with parts c-e?

A 3000 kg rhinoceros running north at 10 m/s collides head on with an 800-kg Land Rover moving east at 25 m/s. The two stick together as the collision occurs. (a) Sketch a picture of this scenario. (b) Classify this collision. (c) Determine the final velocity of the combined system, (d) the speed and direction of the combined system, (e) the kinetic energy before and after the collision.

Answer 1

c. We know that Momentum remains conserve in head on collision.

So, (M​​V)_Rhinoceros + (MV)_{Land rover} = (MV)_Combined

=> (3000 kg)*(10 m/s j) + (800 kg)*(25 m/s i) = (3000+800) kg * V_{​​​​​​Combined}

​​​​​​=> V_{​​​​​Combined} = (7.9 j + 5.3 i) kg-m/s

Hence, Combined Velocity = (5.3i + 7.9j) (kg-m)/s

d. Combined Speed = √[(5.3)² + (7.9)²] m/s = 9.49 m/s

Direction of system = (5.3i + 7.9j)/9.49

e. KE_{​​​​​Before} = (KE)_Rhinoceros + (KE)_{Land rover} = (0.5)[(3000 kg)*(10 m/s)² + (800 kg)*(25 m/s)²] = 265000 J

KE_{​​​​​After} = 0.5*((3000+8000)kg * (9.49 m/s)²) = 171114 J