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.
Advertisements
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
Find the gravitational potential energy of 2.5 kg mass kept at a height of 15 m above the ground. The force of gravity on mass 1 kg is 10 n.
A ball of mass m is thrown vertically up with an initial velocity so as to reach a height h. The correct statement is:
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?
Is potential energy a vector or a scalar quantity?
Give one example each of a body possessing : (i) kinetic energy, and (ii) potential energy.
What is the difference between gravitational potential energy and elastic potential energy? Give one example of a body having gravitational potential energy and another having elastic potential energy.
If 784 J of work was done in lifting a 20 kg mass, calculate the height through which it was lifted. (g = 9.8 m/s2)
A car is accelerated on a levelled road and acquires a velocity 4 times of its initial velocity. During this process, the potential energy of the car :
Potential energy and heat energy are the two forms of mechanical energy.
Which of the following is the example potential energy?
