Question

1. A Vulcan spaceship has a mass of 6.50 × 10⁴ kg and a Romulan spaceship is twice as massive. Both have engines that generate the same total force of 9.50 × 10⁶ N. If each spaceship fires its engine for the same amount of time, starting from rest and ignoring any change in mass due to whatever is expelled by the engines, calculate the energy of the Vulcan spaceship if the engines are fired for 103 s.

2. A tennis ball of mass 0.0531 kg is served. It strikes the ground with a velocity of 54.0 m/s (120 mi/h) at an angle of 22.0° below the horizontal. Just after the bounce it is moving at 53.0 m/s at an angle of 18.0° above the horizontal. If the interaction with the ground lasts 0.0620 s, in what angle does the average force exerted by the ground on the ball act?

a) 0.529 b) 89.5 c) 0.823 d) 80.3

3. A 0.0300-kg bullet is fired vertically at 200.0 m/s into a 0.166-kg baseball that is initially at rest. The bullet lodges in the baseball and, after the collision, the baseball/bullet rise to a height of 37.0 m. Assume up to be the positive direction. What was the speed of the baseball/bullet right after the collision?  

Answer 1

ONE QUESTION AT A TIME PLEASE

1) As the Vulcan ship starts from rest, initial kinetic energy is zero.

impulse = change in momentum

Force * time = mass ( final velocity - initial velocity)

9.5e6 * 103 = 6.50e4 * final velocity

final velocity = 15053.85 m/s

so,

K.E = 1/2mv²

K.E = 7.36e12 J