Q1. A 58.0-kg projectile is fired at an angle of 30.0° above the horizontal with an initial speed of 1.26 102 m/s from the top of a cliff 150 m above level ground, where ground is taken to be y = 0.

(a) What is an initial total mechanical energy of the projectile?

(b) Assume the projectile is travelling 89.3 m/s at its maximum height of y = 315 m. How much work has been done on the projectile by air friction?

(c) What is the speed of the projectile immediately before it hits the ground if air friction does one and a half times as much work on the projectile when it is going down as it did when it was going up?

Q2. A ball is thrown directly upward with an initial velocity of 10 m/s. If the ball starts at an initial height of 2.1 m, how long is the ball in the air?
Overlook air drag.

Q3. Determine the magnitude of the magnetic field at a point 10 cm from a long, thin and straight wire bearing a current of 500 mA.

How to solve this because it has a point of 10 cm instead of radius?