Write down the equation which links energy transferred (E), power (P) and time (t)

A student has been asked the following question:Calculate the energy transferred when an elevator with a power rating of 4 kW ascends for 2 minutes.They carried out their calculation using the following steps:P = 4 kW = 4000 Wt = 2 minutesP = E / t4000 = E / 2E = 4000 x 2E = 8000 JHas this been answered correctly?No, they did not rearrange the equation correctly.Yes, they have calculated this correctly.No, they forgot to convert the kilowatts into watts to use in the calculation.No, they did not convert time into seconds.No, they have given their answer in joules when it should be in kilojoules

Which of the following could not be a formula for energy?E = mc2 where m is a mass and c is the speed of lightE = mavt, where m is a mass, a is an acceleration, v is a velocity, and t is a timeE = mav, where m is a mass, a is an acceleration, and v is a velocity

List the different ways that energy can be transferred

The equation E = pc is valid (here E is energy, P is momentum and c is speed of light in vacuum) :

17 A motor is used to lift a load vertically upwards.The load has weight W.The motor produces useful power output P.The load is lifted at constant velocity v.Which expression gives the time taken for the motor to lift the load vertically upwards through adistance d ?A WdP B PWv C PWd D WPv18 A lamp is switched on for 2.0 hours. The power input to the lamp is 1.0 W. The energy given outby the lamp as light is 7.0  10 3 J.How much energy is converted to other forms by the lamp?A 120 J B 200 J C 3400 J D 7200 J19 An object of mass m is dropped onto the surface of two planets, X and Y, which have noatmosphere.The height from which the object is dropped and the change in gravitational potential energy ofthe object, for each planet, are given in the table.height / m change in gravitationalpotential energyplanet X 3 ∆Eplanet Y 4 4∆EThe acceleration of free fall near the surface of planet X is gX .What is the acceleration of free fall near the surface of planet Y?A X43 g B X34 g C 3gX D 4gX20 A known tensile force acts on a metal wire. The wire does not exceed its limit of proportionality.Which two measurements enable the strain of the wire to be calculated?A the unstretched length of the wire and the cross-sectional area of the wireB the unstretched length of the wire and the extension of the wireC the Young modulus of the metal and the extension of the wireD the Young modulus of the metal and the unstretched length of the wire