JEE Main · 2021 · 27 Aug 2021 · Shift 1 · Work, Power & Energy

WhatsApp Email

Two persons A and B perform same amount of work in moving a body through a certain distance d with application of forces acting at angle

4 5^{\circ}

and

6 0^{\circ}

with the direction of displacement respectively. The ratio of force applied by person

A

to the force applied by person

B

\frac{1}{x}

. The value of

x

Answer: 2

Solution

Equal work over the same displacement

d

means

F_{A} d cos 4 5^{\circ} = F_{B} d cos 6 0^{\circ}

, so

\frac{F _{A}}{F _{B}} = \frac{cos 6 0 ^{\circ}}{cos 4 5 ^{\circ}} = \frac{1/2}{1/ 2} = \frac{1}{2} .

Comparing with

\frac{1}{x}

gives

x = 2

JEE Main · 2021 · 27 Aug 2021 · Shift 1 · Integer answer

Practise more: all JEE Main PYQs on Work, Power & Energy →

More JEE Main questions on Work, Power & Energy

Given below are two statements:
Statement I: An object moves from position $r_{1}$ to position $r_{2}$ under a conservative force field $F$ . The work done by the force is $W = - \int_{r_{1}}^{r_{2}} F \cdot d r$ .
Statement II: Any object moving from one l …
JEE Main 2026View solution →
Consider two identical metallic spheres of radius $R$ each having charge $Q$ and mass $m$ . Their centers have an initial separation of $4 R$ . Both the spheres are given an initial speed of $u$ towards each other. The minimum value of $u$ , so that they can just touch e …
JEE Main 2026View solution →
A body of mass 2 kg is moving along x-direction such that its displacement as function of time is given by $x (t) = α t^{2} + β t + γ m$ , where $α = 1 m / s^{2}$ , $β = 1 m / s$ an …
JEE Main 2026View solution →
In case of vertical circular motion of a particle by a thread of length r if the tension in the thread is zero at an angle 30° shown in figure, the velocity at the bottom point (A) of the circular path is (g = gravitational acceleration)
JEE Main 2026View solution →
A spherical ball of mass 2 kg falls from a height of 10 m and is brought to rest after penetrating 10 cm into sand. The average force exerted by sand on the ball is $____$ N.
JEE Main 2026View solution →
A 1 kg block subjected to two simultaneous forces $(2 \hat{i} + 3 \hat{j} + 4 \hat{k})$ N and $(3 \hat{i} - \hat{j} - 2 \hat{k})$ N is moved a distance of 25 m along $(3 \hat{i} - 4 \hat{j})$ direction. The work done in this process is _____ J.
JEE Main 2026View solution →