Advertisements
Advertisements
Question
A mass of 10 kg is at a point A on a table. It is moved to a point B. If the line joining A and B is horizontal, what is the work done on the object by the gravitational force? Explain your answer.
Solution
- The mass of 10 kg is transported horizontally from point A to B. Gravity acts vertically downward. Thus, the mass moves at a right angle to the force of gravity. So,
- Work done on the item by the force of gravity = Fs cosθ = Fs cos90° = 0 (∵ cos 90 = 0).
- Therefore, the gravitational pull on the object does not work.
APPEARS IN
RELATED QUESTIONS
The potential energy of a freely falling object decreases progressively. Does this violate the law of conservation of energy? Why?
A bucket full of water is on the first floor of your house and another identical bucket with the same quantity of water is kept on the second floor. Which of the two has greater potential energy?
The gravitational potential energy stored in a box of weight 150 kgf is 1.5 × 104 J. Find the height of the box. Take 1 kgf = 10 N.
A body falls freely under gravity from rest. Name the kind of energy it will possess at the point from where it falls.
Two bodies A and B of equal masses are kept at heights of h and 2h respectively. What will be the ratio of their potential energies?
What happens to the potential energy of a body when its height is doubled?
To what height should a box of mass 150 kg be lifted, so that its potential energy may become 7350 joules? (g = 9.8 m/s2)
If we increase the velocity of a car moving on a flat surface to four times its original speed, its potential energy ______.
Potential energy and heat energy are the two forms of mechanical energy.
What energy is possessed by stretched rubber?
