A body projected vertically from the earth reaches a height equal… - Vidyadip

MCQ

A body projected vertically from the earth reaches a height equal to earth's radius before returning to the earth. The power exerted by the gravitational force is greatest

A
at the highest position of the body.
✓
at the instant just before the body hits the earth.
C
it remains constant all through
D
at the instant just after the body is projected.

✓

Answer

Correct option: B.

at the instant just before the body hits the earth.

b
Power, hitting $P= \vec F\cdot \vec v = 0 = Fv\cos\theta $
Just before hitting the earth $\theta =0^o$ Hence, the power exerted by the gravitational force is greatest at the instant just before the body hits the earth.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

JEE STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

The pressure of air in a soap bubble of $0.7\,cm$ diameter is $8\, mm$ of water above the pressure outside. The surface tension of the soap solution is ........ $dyne/cm$

A long solenoid has $500$ turns. When a current of $2$ $ampere$ is passed through it, the resulting magnetic flux linked with each turn of the solenoid is $4\,\times\,10^{-3}\,\,Wb$ . The self-inductance of the solenoid is .......$H$

A ring of mass $m$ moves from point $1$ to point $2$ along a smooth rigid horizontal wire with a constant speed $v$. The average force acting the ring over the time of its motion from $1$ to $2$ is

In the figure shown, horizontal force $F_1$ is applied on a block but the block does not slide. Then as the magnitude of vertical force $F_2$ is increased from zero the block begins to slide; the correct statement is

For two infinitely long charged parallel sheets, the electric field at $P$ will be

Among which the magnetic susceptibility does not depend on the temperature

An electron jumps from $5^{th}$ orbit to $4^{th}$ orbit of hydrogen atom. Taking the Rydberg constant as ${10^7}$ per metre. What will be the frequency of radiation emitted

Unit of magnetic permeability is

The reverse biasing in a $PN$ junction diode

Dimensional formula for thermal conductivity is (here $K$ denotes the temperature)