A block of mass $$2$$ kg is placed on a rough horizontal surface, coefficient of friction between the block and the surface is $$0.4$$. A horizontal force of $$10N$$ is applied on the block. Then rate of work done by the force at t $$=$$ $$1$$ $$sec$$ is (The$$ $$10$$ N force is applied at t $$=$$ $$0).

Question

A block of mass $$2$$ kg is placed on a rough horizontal surface, coefficient of friction between the block and the surface is $$0.4$$. A horizontal force of $$10N$$ is applied on the block. Then rate of work done by the force at t $$=$$ $$1$$ $$sec$$ is (The$$ $$10$$ N force is applied at  t $$=$$ $$0).

Infinity Learn · Accepted Answer

$$a=10$$−$$0.4$$  × $$2$$ ×$$10$$ $$2$$  $$m/s2=1m/s2After$$ $$1$$ $$sec$$, v $$=$$ u $$+$$ at $$=$$ $$0$$ $$+$$ $$1$$ x $$1$$ $$m/s2$$  $$=$$ $$1$$ $$m/s$$∴  Power P $$=$$ F.ν $$=$$ $$10$$  x $$1$$  Watt $$=$$ $$10$$ Watt

Power

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A block of mass 2 kg is placed on a rough horizontal surface, coefficient of friction between the block and the surface is 0.4. A horizontal force of 10N is applied on the block. Then rate of work done by the force at t = 1 sec is (The 10 N force is applied at t = 0).

$a = \frac{10 - 0.4 \times 2 \times 10}{2} m / s^{2} = 1 m / s^{2}$
After 1 sec, v = u + at = 0 + 1 x 1 $m / s^{2}$ = 1 m/s
$∴$ Power P = F. $ν$ = 10 x 1 Watt = 10 Watt

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Power

Remember concepts with our Masterclasses.

A block of mass 2 kg is placed on a rough horizontal surface, coefficient of friction between the block and the surface is 0.4. A horizontal force of 10N is applied on the block. Then rate of work done by the force at t = 1 sec is (The 10 N force is applied at t = 0).

a=10−0.4 × 2 ×10 2 m/s2=1m/s2After 1 sec, v = u + at = 0 + 1 x 1 m/s2 = 1 m/s∴ Power P = F.ν = 10 x 1 Watt = 10 Watt

Ready to Test Your Skills?

free study material

$a = \frac{10 - 0.4 \times 2 \times 10}{2} m / s^{2} = 1 m / s^{2}$
After 1 sec, v = u + at = 0 + 1 x 1 $m / s^{2}$ = 1 m/s
$∴$ Power P = F. $ν$ = 10 x 1 Watt = 10 Watt