Advertisements
Advertisements
प्रश्न
Calculate the decrease in the kinetic energy of a moving body if its velocity reduces to half of the initial velocity.
Advertisements
उत्तर
We know for kinetic energy, body must have velocity
Let initial velocity = v
Also, Kinetic energy is equal to
K.E. = `1/2"m""v"^2`
given velocity decreased to half, so new velocity v'
v' = `"v"/2`
= K.Enew = `1/2 "m" xx ("v"/2)2`
= K.Enew = `1/2 "m" "v"^2/4`
∴ K.Enew = `("m""v"^2)/8`
Now, as asked, we need to find the decrease
Δ K.E = `("m""v"^2)/2 - ("m""v"^2)/8`
Δ K.E = `3/4"m""v"^2`
Kinetic energy will decrease by `3/4`th of initial kinetic energy.
संबंधित प्रश्न
What is the source of heat contained in geothermal energy?
Fill in the blank
An object falling freely from the roof of a multistorey building has ________ and _________ energy when halfway down the building.
Name the type of energy (kinetic or potential) possessed by the following:
Water flowing in a river.
State the energy transformation on the following:
Electricity is obtained from nuclear energy.
Name the energy changes for the following
human body
A pebble is thrown up. It goes to a height and then comes back on the ground. State the different changes in form of energy during its motion.
A body of mass 5 kg falls from a height of 10 m to 4 m. Calculate:
The total energy possessed by the body at any instant? (Take g = 10 ms-2).
Give two examples each of renewable and non-renewable sources of energy?
State the energy changes which take place when:
A toy car spring is wound and car is made to run on level floor.
State the energy changes which take place when:
Water stored in dams rotates turbine connected to a dynamo.
