A ball is thrown vertically upward from the ground with velocity of 30m/s¹. Exactly 0.5s later another ball Is dropped from rest from a cliff 40m above the point from which the first stone was projected. find : a) The time after the first stone was thrown when the two stones meet
b) How far above the ground they are at the same time?

Suppose a force of 60 n is required to stretch and hold a spring 0.1 m from its equilibrium position. a. assuming the spring obeys hooke's law, find the spring constant k. b. how much work is required to compress the spring 0.5 m from its equilibrium position? c. how much work is required to stretch the spring 0.6 m from its equilibrium position? d. how much additional work is required to stretch the spring 0.1 m if it has already been stretched 0.1 m from its equilibrium? a. kequals 600

Describe how the motion of a spring being pushed forward and backward is similar to the motion of air particles in a sound wave.

A1500 w electric heater is plugged into the outlet of a 120 v circuit that has a 20 a circuit breaker. you plug an electric hair dryer into the same outlet. the hair dryer has power settings of 600 w, 900 w , 1200 w, and 1500 w. you start with the hair dryer on the 600 w setting and increase the power setting until the circuit breaker trips. under what setting does the circuit breaker trip.