Motion Test

Result

Motion Test - 21

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

From kinematics, correct equation of motion for $$S$$ is/are :

A
$$S=ut-\frac {1}{2}at^2$$

B
$$S=ut+\frac {1}{2}at^2$$

C
Both (a) and (b)

D
None of these

Solution

According to the second equation of motion,

$$s = ut+\dfrac{1}{2}at^2$$

where, $$s$$=displacement
$$u$$=initial velocity
$$t$$ = time
$$a$$=acceleration

(i) If the displacement and acceleration are in the same direction, then,

$$s=ut+\dfrac{1}{2}at^2$$
where $$a$$ is the magnitude of the acceleration

For example, a car linearly accelerating on road.

(ii) If the displacement and acceleration are in the opposite direction, then,

$$s=ut-\dfrac{1}{2}at^2$$
where $$a$$ is the magnitude of the acceleration

For example, a ball thrown vertically upwards in air

Hence, the correct option is C.
Question 2
1 / -0

Is it possible to have an accelerated motion with a constant speed? Name such type of motion.

A
Yes, Uniform Circular Motion.

B
Yes, Non-Uniform Circular Motion.

C
Yes, Uniform Linear Motion

D
No

Solution

Yes it is possible. Let us take an example, circular motion. In this it has acceleration because direction of motion is changing but it has constant speed along tangential. Hence it is possible.
Question 3
1 / -0

Which of the following quantity remains constant in a uniform circular motion?

A
velocity

B
speed

C
acceleration

D
both velocity and speed

Solution

In a uniform circular motion, the direction of velocity changes but its magnitude remains constant, hence, speed remains constant in a uniform circular motion.
Hence the correct answer is B
Question 4
1 / -0

The distance $$x$$ covered in time $$t$$ by a body having initial velocity $${ v }_{ 0 }$$ and having constant acceleration $$a$$ is given by $$x={ v }_{ 0 }t+1/2a{ t }^{ 2 }$$. This result follows from :

A
newton's Ist law

B
newton's IInd law

C
newton's IIIrd law

D
none of the above

Solution

The given equation is the fundamental equation of kinematics. So it can not follow from any Newton's law of motion.
Ans:(D)
Question 5
1 / -0

A food packet is released from a helicopter rising steadily at the speed of $$2\ { m }/{ s }$$. After $$2$$ seconds the velocity of the packet is (Take $$g=10 { m }/{ { s }^{ 2 } } $$):

A
$$22\ { m }/{ s }$$

B
$$20\ { m }/{ s }$$

C
$$18\ { m }/{ s }$$

D
None of these

Solution

The food packet has an initial velocity $$u= 2\ { m }/{ s }$$ in upward direction,
$$g= 10 \ m/s^2$$
$$t= 2 \ s$$

Using the first equation of motion, $$v = u+at$$

Taking the upward direction as negative and downward direction as positive

$$v=-2+10\times 2=18\ { m }/{ s }$$

Hence, the velocity of the packet is $$18 \ m/s$$ in the downward direction.
Question 6
1 / -0

Which of the following is/are true about retardation

A
When velocity of a body decreases over time, the rate of change of velocity is known as retardation.

B
Its SI unit is $$m/s^2$$.

C
It is the negative of acceleration

D
All the above.

Solution

Retardation is opposite of acceleration. In case of acceleration, velocity increases with time and in case of retardation, velocity decreases over time.
Question 7
1 / -0

For a body moving with an initial velocity $$u$$ and uniform acceleration $$a$$. Find the displacement of the body in time t.

A
$$s=ut+\dfrac{1}{2}at^2$$

B
$$s=u+at$$

C
$$s=ut-\dfrac{1}{2}at^2$$

D
$$s=ut+at^2$$

Solution

From the second equation of motion, if u = initial velocity , a= acceleration and t= time then
$$s=ut+\dfrac{1}{2}at^2$$
Question 8
1 / -0

Which of the following is true about distance and time.

A
distance and time are always directly proportional to each other.

B
distance and time are always indirectly proportional to each other.

C
distance and time are directly proportional when the velocity is constant.

D
distance and time are indirectly proportional when the velocity is constant.

Solution

$$ Speed = \dfrac{Distance}{Time} $$

For uniform velocity, Distance $$\propto$$ Time
Question 9
1 / -0

A body starts from rest and acquires a velocity $$10m s^{-1}$$ in 2 s. Find the acceleration.

A
$$10 m s^{-2}$$

B
$$20 m s^{-2}$$

C
$$5 m s^{-2}$$

D
$$40 m s^{-2}$$

Solution

Acceleration = Change in velocity per unit time.

Therefore, Acceleration $$a = \dfrac{10 m/s}{2 s} = 5 m/s^2 $$
Question 10
1 / -0

A car starting from rest acquires a velocity $$180\ m s^{-1}$$ in 0.05 h. Find the acceleration.

A
$$3600 m s ^{-2}$$

B
$$9 m s ^{-2}$$

C
$$2 m s ^{-2}$$

D
$$1 m s ^{-2}$$

Solution

Acceleration, $$a = \dfrac{180 m/s}{0.05\times 3600 s} = 1 m/s^2 $$

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Motion Test - 21

Result

Motion Test - 21

Score

-

Rank

-

SHARING IS CARING

Question 1

$$S=ut-\frac {1}{2}at^2$$

$$S=ut+\frac {1}{2}at^2$$

Both (a) and (b)

None of these

Solution

Question 2

Yes, Uniform Circular Motion.

Yes, Non-Uniform Circular Motion.

Yes, Uniform Linear Motion

No

Solution

Question 3

velocity

speed

acceleration

both velocity and speed

Solution

Question 4

newton's Ist law

newton's IInd law

newton's IIIrd law

none of the above

Solution

Question 5

$$22\ { m }/{ s }$$

$$20\ { m }/{ s }$$

$$18\ { m }/{ s }$$

None of these

Solution

Question 6

When velocity of a body decreases over time, the rate of change of velocity is known as retardation.

Its SI unit is $$m/s^2$$.

It is the negative of acceleration

All the above.

Solution

Question 7

$$s=ut+\dfrac{1}{2}at^2$$

$$s=u+at$$

$$s=ut-\dfrac{1}{2}at^2$$

$$s=ut+at^2$$

Solution

Question 8

distance and time are always directly proportional to each other.

distance and time are always indirectly proportional to each other.

distance and time are directly proportional when the velocity is constant.

distance and time are indirectly proportional when the velocity is constant.

Solution

Question 9

$$10 m s^{-2}$$

$$20 m s^{-2}$$

$$5 m s^{-2}$$

$$40 m s^{-2}$$

Solution

Question 10

$$3600 m s ^{-2}$$

$$9 m s ^{-2}$$

$$2 m s ^{-2}$$

$$1 m s ^{-2}$$

Solution

User

Question Analysis

My Perfomance

Score

-

Rank

-

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.