How much force is needed to cause a car weighing 800kg to accelerate at a rate of 5 m/s^2? Suppose after accelerating the car begins to travel at a constant velocity of 10 m/s. How much momentum has the car generated at the constant velocity? Use a few short sentences to describe how you arrived at your answer.

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?