Advertisements
Advertisements
प्रश्न
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
उत्तर
- 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
संबंधित प्रश्न
Gravitational potential energy U = mass × force of gravity on unit mass × ..........
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.
The potential energy of a body is the energy by virtue of its ______.
A spring is kept compressed by a small trolley of mass 0.5 kg lying on a smooth horizontal surface as shown in the adjacent fig. When the trolley is released, it is found to move at a speed v = 2 m s-1. What potential energy did the spring possess when compressed?
A body falls freely under gravity from rest. Name the kind of energy it will possess at the point from where it falls.
Is potential energy a vector or a scalar quantity?
State whether the following statement is true or false :
The potential energy of a body of mass 1 kg kept at a height of 1 m is 1 J.
A weightlifter is lifting weights of mass 200 kg up to a height of 2 metres. If g = 9.8 m s−2, calculate :
work done by the weightlifter
Give one example each of a body possessing : (i) kinetic energy, and (ii) potential energy.
Which of the following is the example potential energy?
