A pendulum dropped from a height of 12 cm above the lowest point. How fast will it be traveling when it passes through its lowest point The head of a golf club imparts an amount of kinetic energy to the ball upon impact. If the golfer lightens the mass of the club head to 1/3 of its original mass and increases the clubs speed so its 3 times its speed before. 

How much kinetic energy will be imparted on the ball now Pendulum = 1kg what is its change in gravitational energy of the pendulum bob as it moves from a to be (left to right) how do i calculate this A 20kg box is pushed up a ramp. 

If it needs a force of 160N to push at a constant velocity, what is the ramps efficiency? Height=7m Ramp going upward distance= 10m A 50 kg box is pulled 11m along level surface by a rope. If the rope makes an angle with a surface of 35 degrees, and the force exerted through the rope is 90N, how much work is done on the box A safe is hurled down from the top of a 130m building at a speed of 11m/s. What is its Velocity as it hits the ground An electric kettle is used to heat water. The Kettles power rating is 1150 W and it has been found to be 75% efficient. 

a) how much useful power does the kettle provide 

b) if there is 500ml of water inside the kettle with an initial temperature of 15 degrees Celsius, how much will be needed to raise the temperature of the water to 100 degrees Celsius 

c) How long will it take the kettle to heat water to 100 degrees Celsius