1.A 9 gram bullet is fired horizontally at a tree and is brought to a halt right before it exits the tree. the tree is 90cm thick and exerts a resistive force of 16000N on the bullet as it travels through the tree. Given this information find the initial velocity of the bullet before it hit the tree. Show answer in meters not cm.
2.A ball is thrown with a valocity of 30 m/s at an angle of 40 degrees above the horizontal from the top of a 100m tall building.
a) what is the greatest vertical height ball achieves?
b) what is balls velocity when it lands. (neglect air resistance in both cases) DO NOT USE 2D projectile motions, only work or energy considerations.