A student uses a machine to lift a 500N weight vertically a distance of 3 meters in 5 seconds. What is the power output, assuming that no other external factors are acting during the lift?

A forklift exerts a force of 12,000 N to lift a box 4 ,meters in 3 ,seconds. What is the power ,produced by the forklift? A. 9,000 J/s B. 16,000 J/s C. 36,000 J/s D. 144,000 J/s

An empty lift has a weight of 4.1 kN.It takes half a minute to travel 150 m.Calculate the power of the lift in kilowatts.Power = _____ kW

An electric lift with a maximum load of 2000 kg (lift + passengers) is moving up with a constant speed of 1.5 ms–1. The frictional force opposing the motion is 3000 N. The minimum power delivered by the motor to the lift in watts is : (g = 10 m s–2 )           [2022]A: 20000 B: 34500 C: 23500 D: 23000

A mechanical jack is used to lift a car.(i) (1 mark)If a 1300 kg car is raised 0.28 m, how much work was done on the car?(ii) (1 mark)If the lever was pushed a total distance of 5.1 m at constant force, how large was the force applied? Assume 100% efficiency.(iii) (3 marks)Now suppose the jack is only 60% efficient. The person operating the jack supplies 75 W of power. How long does it take to lift the car the 0.28 m distance?

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