Aball is thrown with a speed of 10 m/s at an angle of 65. which of the following statement describes the motion of the ball at the top of its trajectorya. the horizontal component of velocity is increasing b. the horizontal component of velocity is zeroc. the vertical acceleration is zerod. the vertical acceleration is constant

If steel is more dense that lake water, why can a boat float

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.

What was the first instrument to ever record an earthquake?