Advertisements
Advertisements
प्रश्न
Advertisements
उत्तर
K.E ,K = `1/2`mv²
If speed is doubled;
K.E , K = `1/2` m (2v)²
or K' = 4 x `1/2` mv² = 4K
Thus K.E becomes four times
Thus if initially the K.E is 5J after increasing the speed twice, its k.E will become 4 x5 = 20 J.
APPEARS IN
संबंधित प्रश्न
When do we say that work is done?
Give reasons for the following A teacher moving around in the class is doing work but a child standing and reading a book is not doing any work.
A boy of weight 40 kgf climbs up the 15 steps, each 15 cm high in 10 s and a girl of weight 20 kgf does the same in 5 s. Compare:
- the work done, and
- the power developed by them. Take g = 10 N kg-1.
How much work is done when a force of 1 N moves a body through a distance of 1 m in its own direction?
The velocity of a car increases from 54 km/hr to 72 km/hr. How much is the work done if the mass of the car is 1500 kg?
Name the force acting away from the centre of circular path.
Nm is the unit of .......
State whether work is done or not, by writing yes or no, in the following case:
A man pushes a wall.
