What is the force of a dodgeball hitting a person in the face if it's initial velocity was 10m/s and it's velocity after hitting him in the face it is 5m/s? The ball weighs 3kg and it took 2 seconds to get there. p/t p=momentum t=time

Find v(t), given acceleration a(t)=7j and initial velocity v(0)=k

Samir watches a 100-minute movie on his spaceship. maria's spaceshipe flies in the same direction as samir's spaceship but she observes his move to last 125 minutes and his spaceship to be 40 m long. how long does samir observe his own spaceship to be? according to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does marias voyage take according to samir?

What is the measurement of how fast an object moves relative to a reference point?