Alpha Question Bank for Medical: Physics>Chapter 8 - Work, Energy and Power>Exercise-1>Q 29

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$300 J$ of work is done in sliding a $2 kg$ block up an inclined plane of height $10 m$ . Taking $g = 10 m s^{2}$ work done against friction is

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Important Questions on Work, Energy and Power

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Alpha Question Bank for Medical: Physics>Chapter 8 - Work, Energy and Power>Exercise-1>Q 30

An object is moving along a straight line path from

P

to

Q

under the action of a force

\vec{F} = (4 \hat{i} - 3 \hat{j} + 2 \hat{k}) N

If the co-ordinate of

P & Q

in metres are

(3, 2, - 1) & (2, - 1, 4)

respectively. Then the work done by the force is:

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Alpha Question Bank for Medical: Physics>Chapter 8 - Work, Energy and Power>Exercise-1>Q 31

The work done by static friction on an object

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Alpha Question Bank for Medical: Physics>Chapter 8 - Work, Energy and Power>Exercise-1>Q 32

A body of mass

m

is moving in a circle of radius

r

with a constant speed

v

. The force on the body is

\frac{m v^{2}}{r}

and is directed towards the centre. What is the work done by the force in moving the body half the circumference of the circle?

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Alpha Question Bank for Medical: Physics>Chapter 8 - Work, Energy and Power>Exercise-1>Q 33

A rigid body of mass

m kg

is lifted uniform velocity by a man to a height of one metre in

30 \sec

. Another man lifts the same mass with uniform velocity to the same height in

60 \sec

. The work done on the body against gravitation by them are in ratio-

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Alpha Question Bank for Medical: Physics>Chapter 8 - Work, Energy and Power>Exercise-1>Q 34

A ball is released from the top of a tower. The ratio of work done by force of gravity in first, second and third second of the motion of ball is

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Alpha Question Bank for Medical: Physics>Chapter 8 - Work, Energy and Power>Exercise-1>Q 35

A block of mass $m$ is suspended by a light thread from an elevator. The elevator is accelerating upward with uniform acceleration $a .$ The work done by tension on the block during $t$ seconds is $(u = 0) :$

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Alpha Question Bank for Medical: Physics>Chapter 8 - Work, Energy and Power>Exercise-1>Q 36

A force

\vec{F} = 3 \hat{i} + C \hat{j} + 2 \hat{k}

acting on a particle causes displacement

\vec{s} = - 4 \hat{i} + 2 \hat{j} + 3 \hat{k}

in its own direction. If work done is

6 J

then value of

C

is:

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Alpha Question Bank for Medical: Physics>Chapter 8 - Work, Energy and Power>Exercise-1>Q 37

A force acting on a particle varies with the displacement

x

as

F = a x - b x^{2}

, where

a = 1 N m^{- 1}

and

b = 1 N m^{- 2} .

The work done by this force for the first one meter (

F

is in newtons,

x

is in meters) is: