EASY

Earn 100

A boy stands on a weighing machine in a lift. The machine reads his weight as $W$ .The lift starts moving upwards with a constant speed.

The reading on the machine will be:

50% studentsanswered this correctly

Important Questions on Laws of Motion

EASY

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A person is standing in an elevator. In which situation, he experiences weight loss ?

HARD

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

Two wooden blocks are moving on a smooth horizontal surface such that the block having mass $m$ remains stationary with respect to block of mass $M$ as shown in the figure below. The magnitude of the applied force $P$ is,

Question Image

EASY

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A block of mass

M

placed inside a box descends vertically with acceleration

a

. The block exerts a force equal to one-fourth of its weight on the floor of the box. The value of

a

will be

MEDIUM

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A balloon with mass

m

is descending down with an acceleration

a

(where

a < g) .

How much mass should be removed from it so that it starts moving up with an acceleration

a

MEDIUM

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A boy is standing on a weighing machine inside a lift. When the lift goes upwards with acceleration

\frac{g}{4},

the machine shows the reading

50 kg .

wt. When the lift goes downward with acceleration

\frac{g}{4},

the reading of the machine in

kg

wt

. would be

EASY

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A block

A

takes

2 s

to slide down a frictionless incline of

30 °

and length

l

, kept inside a lift going up with uniform velocity

v

. If the incline is changed to

45 °

, the time taken by the block, to slide down the incline, will be approximately:

MEDIUM

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

When a lift of mass

800 kg

is ascending with an acceleration of

5 m s^{- 2}

, the tension in its cable will be

______

take

(g = 10 m s^{- 2})

MEDIUM

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

Two blocks

A

and

B

of masses

3 m

and

m

respectively are connected by a massless and inextensible string. The whole system is suspended by a massless spring as shown in figure. The magnitudes of acceleration of

A

and

B

immediately after the string is cut, are respectively
Question Image

HARD

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A girl drops an apple from the window of a train which is moving on a straight track with speed increasing with a constant rate. The trajectory of the falling apple as seen by the girl is

EASY

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A plumb line is suspended from a ceiling of a car moving with horizontal acceleration

a

. What will be the angle of inclination with vertical?

HARD

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A rope of length

L

and uniform linear density is hanging from the ceiling. A transverse wave pulse, generated close to the free end of the rope, travels upwards through the rope. Select the correct option.

HARD

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A particle is moving along the

x

-axis with its coordinate with time

t

given by

x (t) = 10 + 8 t - 3 t^{2} .

Another particle is moving along the

y

-axis with its coordinate as a function of time given by

y (t) = 5 - 8 t^{3} .

t = 1 s,

the speed of the second particle as measured in the frame of the first particle is given as

\sqrt{v} .

Then

v (i n m s^{- 1})

is ___________.

EASY

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A body of weight

W_{1}

is suspended from the ceiling of a room through a chain of weight

W_{2} .

The ceiling pulls the chain by a force

EASY

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A man weighing

60 kg

is in a lift moving down with an acceleration of

1.8 {ms}^{- 2}

. The force exerted by the floor on him is?

MEDIUM

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

Two blocks

A

and

B

of masses

m_{A} = 1 k g

and

m_{B} = 3 k g

are kept on the table as shown in figure. The coefficients of friction between

A

and

B

0.2

and between

B

and the surface of the table is also

0.2 .

The maximum force

F

that can be applied on

B

horizontally, so that the block

A

does not slide over the block

B

is : [Take

g = 10 m / s^{2}

]

MEDIUM

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A rocket is fired vertically from the earth with an acceleration of 2g, where g is the gravitational acceleration. On an inclined plane inside the rocket, making an angle

θ

with the horizontal, a point object of mass m is kept. The minimum coefficient of friction

μ_{m i n}

between the mass and the inclined surface such that the mass does not move is:

MEDIUM

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A spring balance is attached to the ceiling of a lift. A man hangs his bag on the spring and the spring reads $49 N$ , when the lift is stationary. If the lift moves downward with an acceleration of $5 m s^{- 2}$ , the reading of the spring balance will be – $(g = 9.8 m s^{- 2})$

EASY

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A physics professor in his car drops a coffee mug while moving at a constant velocity of

9.8 m s^{- 1}

along the highway. The professor notices that it only takes a half a second for the mug to drop straight down to the floor of his car. A student standing alongside the road sees the mug moving in a parabola with respect to her. What time does she measure for the mug to hit the floor of the car?

EASY

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A lift is moving down with acceleration

a

. A man in the lift drops a ball inside the lift. The acceleration of the ball as observed by the man in the lift and a man standing stationary on the ground are respectively

MEDIUM

Physics>Mechanics>Laws of Motion>Application of Newton's Law of Motion

A bird is sitting in a large closed cage which is placed on a spring balance. It records a weight of 5N. The bird of mass 0.5 kg files upward in the cage with an acceleration of

2 m s^{- 2}

. The spring balance will now record a weight of......... at that moment?

A boy stands on a weighing machine in a lift. The machine reads his weight as W.The lift starts moving upwards with a constant speed. The reading on the machine will be:

Important Questions on Laws of Motion

Learn and Prepare for any exam you want !

A boy stands on a weighing machine in a lift. The machine reads his weight as $W$ .The lift starts moving upwards with a constant speed.

The reading on the machine will be: