Motion Test

Result

Motion Test - 22

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

The unit of retardation is

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

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

C
$$m$$

D
$$m s^{2}$$

Solution

Unit of retardation is same as the unit of acceleration i.e. $$m/s^2$$.
Question 2
1 / -0

Which of the following is/are true about acceleration

A
Acceleration is defined as the rate of change of velocity.

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

C
Negative acceleration is called retardation

D
All the above.

Solution

Acceleration =$$\dfrac{Final\ velocity\ - Initial\ velocity }{time}$$

Its SI unit is =$$ms^{-1}/s=m/s^2$$

A negative acceleration acts opposite to the direction of motion of object and it reduces the velocity , it called retardation.
Question 3
1 / -0

Define velocity. State its unit.

A
Velocity is defined as the rate of change of distance of a body with respect to time. Its unit in SI is $$km/s$$.

B
Velocity is defined as the rate of change of displacement of a body with respect to time. Its unit in SI is $$km/s$$.

C
Velocity is defined as the rate of change of distance of a body with respect to time. Its unit in SI is $$m/s$$.

D
Velocity is defined as the rate of change of displacement of a body with respect to time. Its unit in SI is $$m/s$$.

Solution

Velocity is a vector quantity that refers to the rate at which an object changes its position. It is a vector expression of the displacement that an object or particle undergoes with respect to time.
The SI unit of velocity is meter/second.
Question 4
1 / -0

Which of the quantities, speed or velocity gives the direction of motion of body ?

A
speed

B
acceleration

C
velocity

D
all of the above

Solution

velocity, a vector quantity, depends on both the body's speed and its direction of travel.
Question 5
1 / -0

How is the distance related with time for the motion under uniform acceleration such as the motion of a freely falling body starting from rest?

A
$$S \propto t^2$$

B
$$S \propto t$$

C
$$S \propto \dfrac{1}{t^2}$$

D
$$S \propto \dfrac{1}{t}$$

Solution

For a free falling body, initial velocity, $$u = 0 m/s $$ and acceleration due to gravity, $$a = g$$.
Putting the values of $$u$$ and $$a$$ in the equation of motion, $$S = ut+\dfrac{1}{2}at^2 $$
We get, $$S = \dfrac{1}{2}gt^2$$
Therefore, $$S \propto t^2$$
Question 6
1 / -0

A skier starting from rest accelerates down a slope at $$1.6\ ms^{-2}$$. How far has he gone at the end of $$5\ s$$?

A
$$20\ m$$

B
$$40\ m$$

C
$$15\ m$$

D
$$60\ m$$

Solution

Given:
Initial velocity: $$u=0\ m/s$$
Acceleration: $$a = 1.6\ m/s^2$$
Time: $$t = 5\ s$$

Using second equation of motion,
$$s = ut + \cfrac{1}{2} at^{2}$$
$$s = 0 + \cfrac{1}{2} \times 1. 6 \times 25$$
$$s = 20\ m$$
Question 7
1 / -0

Name a physical quantity that remains constant in a uniform circular motion.

A
Velocity

B
Acceleration

C
Momentum

D
Angular speed

Solution

As an object moves around in a circle at constant speed (uniform circular motion), both the velocity and the acceleration change. The magnitudes of the velocity and acceleration don't change, but since velocity and acceleration are vectors, the fact that their directions change means that they change.
Momentum is directly proportional to the velocity of the body and hence it changes.
In the uniform circular motion, the angular speed is same for all the particles,
Question 8
1 / -0

When an object is accelerated:

A
its direction must be constant

B
its velocity is necessarily changing

C
its velocity is constant

D
its speed is necessarily changing

Solution

Acceleration is the time rate of change of velocity.
Question 9
1 / -0

When speed is stated along with its direction, it is called as

A
velocity

B
acceleration

C
jerk

D
none of these

Solution

Velocity of a body is the speed of the body defined along with the direction.
Question 10
1 / -0

A stone tied to a string is whirled in a circle. As it is revolving, the string suddenly breaks. The stone then

A
flies off radially outwards.

B
flies off radially inwards

C
flies off tangentially.

D
moves in a circle of larger radius.

Solution

When a stone tied to a string is rotated in a circle, the velocity of the stone acts tangentially outwards the circle. When the string is suddenly breaks, the stone flies off tangentially outwards i.e. in the direction of velocity.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Motion Test - 22

Result

Motion Test - 22

Score

-

Rank

-

SHARING IS CARING

Question 1

$$m s^{-1}$$

$$m s^{-2}$$

$$m$$

$$m s^{2}$$

Solution

Question 2

Acceleration is defined as the rate of change of velocity.

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

Negative acceleration is called retardation

All the above.

Solution

Question 3

Velocity is defined as the rate of change of distance of a body with respect to time. Its unit in SI is $$km/s$$.

Velocity is defined as the rate of change of displacement of a body with respect to time. Its unit in SI is $$km/s$$.

Velocity is defined as the rate of change of distance of a body with respect to time. Its unit in SI is $$m/s$$.

Velocity is defined as the rate of change of displacement of a body with respect to time. Its unit in SI is $$m/s$$.

Solution

Question 4

speed

acceleration

velocity

all of the above

Solution

Question 5

$$S \propto t^2$$

$$S \propto t$$

$$S \propto \dfrac{1}{t^2}$$

$$S \propto \dfrac{1}{t}$$

Solution

Question 6

$$20\ m$$

$$40\ m$$

$$15\ m$$

$$60\ m$$

Solution

Question 7

Velocity

Acceleration

Momentum

Angular speed

Solution

Question 8

its direction must be constant

its velocity is necessarily changing

its velocity is constant

its speed is necessarily changing

Solution

Question 9

velocity

acceleration

jerk

none of these

Solution

Question 10

flies off radially outwards.

flies off radially inwards

flies off tangentially.

moves in a circle of larger radius.

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.