Advertisements
Advertisements
प्रश्न
A man carrying a suitcase in his hand is walking horizontally. What is the work done against gravity?
Advertisements
उत्तर
The displacement of the man and suitcase is along the horizontal direction. Thus, the angle between the displacement and the force of gravity is 90°;
Thus, W = Fd cos 90° = 0
Hence, no work is done against gravity in this case.
APPEARS IN
संबंधित प्रश्न
When do we say that work is done?
Can there be displacement of an object in the absence of any force acting on it? Think. Discuss this question with your friends and teacher.
Find the kinetic energy of a body of mass 1 kg moving with a uniform velocity of 10 m s-1.
What is the relationship between Nm and dyne cm?
Complete the following sentences:
Kilowatt is the unit of ....... and kWh is the unit of
A girl of mass 50 kg runs up a flight of 40 steps in 20 seconds. If each step in 20 cm high, calculate the power developed by the girl. (g= 10 ms-2).
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
Food grains are getting dried in the sun.
A proton is kept at rest. A positively charged particle is released from rest at a distance d in its field. Consider two experiments; one in which the charged particle is also a proton and in another, a positron. In the same time t, the work done on the two moving charged particles is ______.
State whether work is done or not, by writing yes or no, in the following case:
A boy climbs up 20 stairs.
