Gravity does negative work here because gravity goes in the opposite direction as the displacement.

If an object is lifted, work is done against gravitational force. The object gains energy. For example, Book C would gain GPE if it were lifted onto the higher book shelf alongside Books A and B. For example, a book with a mass of 0.25 kg is lifted 2 m onto a book shelf.

The factors that affect an object’s gravitational potential energy are its height relative to some reference point, its mass, and the strength of the gravitational field it is in.

gravitational potential energy

Weight training uses a variety of specialized equipment to target specific muscle groups and types of movement. Sports in which weight training is used are: bodybuilding, weightlifting, powerlifting, strongman, highland games, hammer throw, shot put, discus throw, and javelin throw.

So if an appliance works at very little power, but for a very long amount of time, then it may consume a lot of energy.

In testing skilled, elite weightlifters Garhammer discovered that the power output in terms of the benchpress for a male during a one repetition, max load lift is four watts per kilogram of bodyweight. As it applies to the deadlift and squat, the number increases to 12 watts per kilogram of bodyweight.

Generally speaking, a beginner cyclist may average around 75–100 watts in a 1-hour workout. A fit participant will average more than 100 watts, and pro cyclists can reach 400 watts per hour.

As the name suggests, power training is aimed at increasing power, which is the product of both strength and speed. Optimal power reflects how quickly you can exert force to produce the desired movement.

Lifting Weights: On earth it takes about 10 Newton-meters (N-m) of energy to raise a 1 kilogram mass to a height of 1 meter. Since 1 N-m equals 1 Joule, that’s 10 Joules. If it takes 1 second to lift the weight 1 meter, than you have converted 10 Joules of energy to potential energy in one second.

In order to lift the object, a net upward force is required. This is possible only if the upward force is greater than the weight. Thus, to have a net upward force and thus to lift an object, a force greater than its own weight, and acting in the upward direction is required.

250 N

Kg MpsE2 is equal to 1 Newton and it is denoted by N. This way the force required to lift the object of mass 200 g is 2N.

1 Answer. Work done is force multiplied by distance, Hence work done is 300×0.50=150 joules.

No. Work is independent of time. Power is dependent on time, so lifting it faster would require more power.

Answer. Work done does not depend on the velocity of the body. So the work done in lifting a box on to a platform does not depend upon how fast it is lifted up.

What is the relation between mass and power per time? Power= Joules/second=(Newton×meter)/second. This means: Power/time=Joules/second^2=(Newton×meter)/second^2.

Work done does not depend upon how fast an object is raised up. It is clear that work done depends on force, distance and angle between force and displacement. We can say that the work done in raising a box on to a platform does not depends upon how fast it is raised up.