Refer to the figure shown below.
The velocity of the child and the velocity of the ship should be added vectorially to find the speed and direction of the child relative to the water surface.
The magnitude of the child's velocity is
v = √(2² + 18²) = 18.11 mph
The direction of the child's speed is
θ = tan⁻¹ (18/2) = tan⁻¹ 9 = 83.7° north of east or counterclockwise from the eastern direction.
Answer:
The magnitude is 18.1 mph.
The direction is 84° north of east.
The initial kinetic energy of the car is

Then, the velocity of the car is decreased by half:

so, the new kinetic energy is

So, the new kinetic energy is 1/4 of the initial kinetic energy of the car. Numerically:
Because gravity is constant
<span>the only force acting in free-fall is gravity which points downward at 9.8 m/s</span>