A 0.175 kg softball is pitched horizontally at 26 m/s. the ball moves in the opposite direction at 38 m/s after it is hit by the bat. 1. what is the change in momentum?
2. what is the impulse delivered by the bat?
3. if the bat and ball are in contact for 0.80 seconds, what is the average force that the bat applies to the ball?

what is the speed of a softball that travels 20m in 2secs

speed = 20/2 = 10 m/s

the small 0.38-kg slider is known to move from position a to position b along the vertical-plane slot. determine (a) the work done on the body by its weight and (b) the work done on the body by the spring. the distance r = 0.70 m, the spring modulus k = 154 n/m, and the unstretched length of the spring is 0.53 m

explanation:

-reverse card

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.