A ball is thrown horizontally from at A and hits the ground (4.5 sec) later at B. the line of sight from A to B makes an angle of (500) with the horizontal. Compute the magnitude of the initial velocity (u) of the ball.

diagram is missing, but i will try to explain your doubt.

answer:

amplitude is the maximum displacement or distance moved on a point of a vibrating body or wave measured from its equilibrium position.it is equal to half the length of vibration path.

in physics zero. in muscle fatigue could be high

which piece of furniture will have the most inertia and give the furniture movers the most difficulty in moving?  

answer

a 75kg dining table