EASY

Earn 100

An athlete runs on a straight track. She starts from rest and runs with a constant acceleration for the first $2 seconds$ , reaching a speed of $9 m s^{- 1}$ . She then continues at this constant speed for some time before slowing down to a halt at a constant deceleration. The total time taken, from start to finish, is $12 seconds$ . If the magnitude of her acceleration is twice the magnitude of deceleration, then what is the total distance covered by her?

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Important Questions on Measurements and Motion

MEDIUM

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

A ship of mass

2 \times 10^{7} kg

initially at rest is pulled by a force of

5 \times 10^{5} N

, through a distance of

2 m

. Assuming that the resistance due to water is negligible, the speed of the ship is

MEDIUM

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

A ball is dropped from the top of a

100 m

high tower on a planet. In the last

\frac{1}{2} s

before hitting the ground, it covers a distance of

19 m .

Acceleration due to gravity (in

m s^{- 2}

) near the surface on that planet is______

MEDIUM

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

An object with mass

5 kg

is acted upon by a force,

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

. If its initial velocity at

t = 0

\vec{v} = (6 \hat{i} - 12 \hat{j}) {ms}^{- 1},

the time at which it will just have a velocity along y-axis is

MEDIUM

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

A tennis ball is released from a height

h

and after freely falling on a wooden floor it rebounds and reaches height

h / 2

. The velocity versus height of the ball during its motion may be represented graphically by: (graphs are drawn schematically and on not to scale)

EASY

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

A body is thrown vertically upwards. Which one of the following graphs correctly represents the velocity

(v)

vs time

(t)

HARD

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

A helicopter rises from rest on the ground vertically upwards with a constant acceleration

g

. A food packet is dropped from the helicopter when it is at a height

h

. The time taken by the packet to reach the ground is close to [

g

is the acceleration due to gravity]:

EASY

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

A particle starts from origin $O$ from rest and moves with a uniform acceleration along the positive $x - a x i s$ . Identify all figures that correctly represent the motion qualitatively.
( $a =$ acceleration, $v =$ velocity, $x =$ dispalcement, $t =$ time)
$(A)$ Question Image
$(B)$
$(C)$
$(D)$

MEDIUM

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

A ball is projected vertically up from ground. Boy

' A'

standing at the window of first floor of a nearby building observes that the time interval between the ball crossing him while going up and the ball crossing him while going down is

2 s

. Another boy

B

standing on the second floor notices the time interval between the ball passing him twice, during up and down motion is

1 s

. Calculate the difference between the vertical positions of boy

B

and boy

A

. (Assume

g = 10 m s^{- 2}

)

HARD

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

A parachutist with total weight

75 kg

drops vertically onto a sandy ground with a speed of

2 m s^{- 1}

and comes to a halt over a distance of

0.25 m

. The average force from the ground on her is close to-

HARD

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

A stone thrown down with a seed

u

takes a time

t_{1}

to reach the ground, while another stone, thrown upwards from the same point with the same speed, takes time

t_{2}

. The maximum height the second stone reaches from the ground is

MEDIUM

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

Starting from the origin at time

t = 0

, with initial velocity

5 \hat{j} m s^{- 1}

, a particle moves in the

x

y

plane with a constant acceleration of

(10 \hat{i} + 4 \hat{j}) m s^{- 2}

. At time

t

, its coordinates are

(20 m, y m)

. The values of

t

and

y

are, respectively:

HARD

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

A piece of wood of mass

0.03 kg

is dropped from the top of a

100 m

height building. At the same time, a bullet of mass

0.02 kg

is fired vertically upward, with a velocity

100 m s^{- 1},

from the ground. The bullet gets embedded in the wood. Then the maximum height to which the combined system reaches above the top of the building before falling below is:

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

MEDIUM

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

A ball is thrown vertically downward with a velocity of

20 m s^{- 1}

from the top of a tower. It hits the ground after some time with a velocity of

80 m s^{- 1}

. The height of the tower is:

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

EASY

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

An object is thrown vertically with a velocity

u

. The velocity with which it strikes the ground on its return is

EASY

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

A person sitting in the ground floor of a building notices through the window, of height

1.5 m,

a ball dropped from the roof of the building crosses the window in

0.1 s .

What is the velocity of the ball when it is at the topmost point of the window?

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

HARD

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

From the top of a tower of height

H

, a body is thrown vertically upwards with a speed

u

. Time taken by the body to reach the ground is

3

times the time taken by it to reach the highest point in its path. Then, the speed

u

HARD

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

In a car race, two cars start with velocities

u_{1}

and

u_{2}

and travel along a straight line with accelerations

α

and

β

respectively. If both reach the finish line at the same time then range of the race is

HARD

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

From a tower of height H, a particle is thrown vertically upwards with a speed u. The time taken by the particle, to hit the ground, is n times that taken by it to reach the highest point of its path.The relation between H, u and n is :

EASY

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

In a car race on straight road, car

A

takes a time

t

less than car

B

at the finish and passes finishing point with a speed

v

more than that of car

B .

Both the cars start from rest and travel with constant acceleration

a_{1}

and

a_{2}

respectively. Then $v$ is equal to:

MEDIUM

Science>Physics>Measurements and Motion>Motion With Constant Acceleration

A bullet loses

{(\frac{1}{n})}^{th}

of its velocity passing through one plank. Considering uniform retardation, the number of such planks that are required to stop the bullet can be:

Important Questions on Measurements and Motion

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