6a small rock is thrown vertically upward with a speed of 14.0 m/s from the edge of the roof of a 30.0 m tall building. the rock doesn't hit the building on its way back down and lands in the street below. air resistance can be neglected.   a)what is the speed of the rock just before it hits the street? b)how much time elapses from when the rock is thrown until it hits the street?

Why do electron microscopes have higher resolving power than light microscopes?

1. consider the case in which air fills air shocks on a truck trailer. the pressure in the shocks is 2 mpa. the temperature is 300 k. the diameter of the shock piston is 10 cm and the initial length of the cylindrical cavity containing the compressed air is 40 cm. a. the truck is gradually loaded over a period of a day in a static setting. the temperature is held constant for the atmosphere and thus for the gas shock. calculate the compressibility of the air in the shock for this condition when the truck is initially being loaded. b. if the shocks were loaded in a dynamic setting by driving over bumps, what would be the compressibility? state your assumption. c. what is the initial load on the shock if the shock is in an atmospheric 100 kpa? d. if the shock is compressed using the process described in part a, and the air shock compressed air cavity length decreases to 20 cm, what is the additional load applied to the shock?

Calculate the mass of an object that has a momentum of 100kg x m/sec and velocity of 4 m/sec