A(n) 5 kg object moving with a speed of 8.7 m/s collides with a(n) 18 kg object moving with a velocity of 11 m/s in a direction 20◦ from the initial direction of motion of the 5 kg object. 8.7 m/s 11 m/s 18 kg 5 kg 20◦ What is the speed of the two objects after the collision if they remain stuck together? Answer in units of m/s.

As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. there is no one around to , so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. you pull up on the rope to lift the box. use g for the magnitude of the acceleration due to gravity and neglect friction forces. once you have pulled hard enough to start the box moving upward, what is the magnitude f of the upward force you must apply to the rope to start raising the box with constant velocity? express the magnitude of the force in terms of m, the mass of the box.

Which of the following statement is false

Petroleum contains energy. a. light b. kinetic c. chemical d. mechanical