Advertisements
Advertisements
प्रश्न
Advertisements
उत्तर
K.E ,K = `1/2` mv²
If mass is increased four times
K.E ,K' = `1/2` (4m) (v)²
or K' = 4 x `1/2`mv²
to maintain the same kinetic energy the velocity should be made half.
Then, K" = 4 x `1/2` m `("v"/2)²` = K
APPEARS IN
संबंधित प्रश्न
In which of the following cases is work being done:
- A boy pushing a heavy rock
- A boy climbing up the stairs
- A coolie standing with a box on his head
- A girl moving on the road.
A man lifts a mass of 10 kg from the floor to a shelf 4 meter high. If g = 10 ms-2, what is the work done?
Complete the following sentences:
The SI unit of work is ....... and of power is .......
Complete the following sentences:
1 H.P. = ........ W.
A 100 W electric lamp emits energy in the form of light at the rate 10 J per second. What percentage of electric energy does the lamp transform into light energy?
In what way does an ‘Ideal machine’ differ from a ‘Practical machine’?
What is power? How do you differentiate kilowatt from kilowatt-hour? The Jog Falls in Karnataka state are nearly 20 m high. 2000 tonnes of waterfalls from it in a minute. Calculate the equivalent power if all this energy can be utilized? (g = 10 m s–2)
A uniform chain of length 2 m is kept on a table such that a length of 60 cm hangs freely from the edge of the table. The total mass of the chain is 4 kg. What is the work done in pulling the entire chain on the table?
