What is the mass of an object that has a force of 89 n and an acceleration of 25 m/s2

The image shows a pendulum in simple harmonic motion the pendulum starts at a and swing to e

What would be the strength of earth's gravitational field at a point where an 80.0 kg astronaut would experience a 80% reduction in weight

During a medieval siege of a castle, the attacking army uses a trebuchet to hurl heavy stones at the castle walls. if the trebuchet launches the stones with a velocity of at an angle of 50.0°, (a) how long does it take the stone to hit the ground? (b) what is the maximum distance that the trebuchet can be from the castle wall to be in range? (c) how high will the stones go? show all your work.