Advertisements
Advertisements
प्रश्न
How much is the mass of a man if he has to do 2500 joules of work in climbing a tree 5 m tall? (g = 10 m s−2)
Advertisements
उत्तर
Work done in climbing or potential energy, (P.E) = 2500 J
Acceleration due to gravity, (g) = 10 m/s2
Height above the ground be, (h) = 5 m
Let the mass of the man be (m)
We have a relation as,
P.E = m × g × h
So, mass can be calculated as,
`m = (P.E)/(h xx g)`
so , mass of the man ,
`m = 2500/(5 xx 10)` kg
= `250/5` kg
= 50 kg
APPEARS IN
संबंधित प्रश्न
Define 1 watt of power.
Define average power.
A battery lights a bulb. Describe the energy changes involved in the process.
A load of 100 kg is pulled up by 5 m. Calculate the work done. (g = 9.8 m/s2)
Calculate the work done by the brakes of a car of mass 1000 kg when its speed is reduced from 20 m/s to 10 m/s?
A body does 1200 joules of work in 2 minutes. Calculate its power.
The power output of an engine is 3kW. How much work does the engine do in 20 s?
A car of weight 20000 N climbs up a hill at a steady speed of 8 m/s, gaining a height of 120 m is 100 s. Calculate : power of engine of car.
Define power. Give the SI unit of power.
An electric motor raises a load of 0.2 kg, at a constant speed, through a vertical distance of 3.0 m in 2 s. If the acceleration of free fall is 10 m/s2, the power in W developed by the motor in raising the load is :
