Physics: Electricity and Energy: Equations

A 1 kilogram brick is carried up the Eiffel Tower to the 275m platform. How much gravitational potential energy does the brick gain?

A 1000 kilogram car has a kinetic energy of 12500J. Calculate the speed the car is moving at.

An electrical motor rated at 12V and 0.2A is used to lift a 500g mass up a height. If the motor is switched on for 5 seconds calculate how far the mass is lifted.

A 2kW electric kettle is used to heat water. After 5 minutes the heat energy in the water is measured to be 450kJ. Calculate the efficiency of the kettle.

How much energy must be transfered to raise the tempreture of 2kg of water from 20 degrees C to 30 degrees C?

Calculate the final tempreture of 3kg of lead which has been heated by an electrical heater of power 0.1kW for 2 minutes. The initial tempreture of the lead is 20 degrees C. Assume that no heat energy is lost t the atmosphere

Calculate how much heat energy is needed to turn 2kg block of ice at minus 5 degrees C into water at 50 degrees C. Assume there are no losses of heat energy to the atmosphere.

The pressure of a gas enclosed in a cylinder by a piston changes from 80kPa to 200kPa. If there is no change in tempreture and the initial volume was 25 litres, calculate the new volume

The pressure of a gas enclosed in a cylinder is 180kPa at a temperature of 27 degrees C. If it is heated to a tempreture of 77 degrees C, calculate the new pressure.

The volume of a weather balloon that travels to extreme heights is
1(mxmxm) at sea level where the temperature is 21 degrees C. Calculate the new volume of the balloon when it rises to a height of 10km where the temperature is minus 45 degrees C

An electric fan has a resistance of 100 Ohms and is plugges into a wall outlet. How much current runs through the fan?

The gas container which allows the volume to change store helium of volume 1.5(mxmxm) at a pressure of 100kPa and a temperature of 27 degrees C. If the pressure is increased to 250kPa at a temperature of 127 degrees C, calculate the new volume of the container.

An electrical mains heater is switched off for a period of 2 hours. If the heating elements operate at a current of 8A, find the electrical energy produced by the heater

Calculate the resistance of the element in a 2kW mains operated electrical heater. (Note: the 'element' is the name given to the section of wire that heats up when the current flows through it).

Calculate the number of units of electricity used by a 60W bulb that is kept switched on for 8 hours and 45 minutes. We need to find the number of kWh

The weightlifter lifts the barbell at a constant speed from the ground up to the height shown in a time of 4 seconds

Calculate the total charge which flows through a cell in 2 minutes when the current in the circuit is 5A