NCERT Exemplar Science - Class 9>Chapter 8 - Motion>Long Answer Questions>Q 20

HARD

9th CBSE

IMPORTANT

Earn 100

An object starting from rest travels $20 m$ in first $2 s$ and $160 m$ in next $4 s$ . What will be the velocity after $7 s$ from the start?

Important Questions on Motion

HARD

9th CBSE

IMPORTANT

NCERT Exemplar Science - Class 9>Chapter 8 - Motion>Long Answer Questions>Q 21

Using following data, draw time-displacement graph for a moving object.

Time (s)	$0$	$\Rightarrow$	$4$	$6$	$8$	$10$	$12$	$14$	$16$
Displacement (m)	$0$	$a^{'} = 10 m s^{- 2}$	$4$	$4$	$4$	$6$	$4$	$2$	$0$

Use this graph to find average velocity for first $4 s$ , for next $4 s$ and for last $6 s$ .

HARD

9th CBSE

IMPORTANT

NCERT Exemplar Science - Class 9>Chapter 8 - Motion>Long Answer Questions>Q 22

An electron moving with a velocity of

5 \times 10^{4} m s^{- 1}

enters into a uniform electric field and acquires a uniform acceleration of

10^{4} m s^{- 2}

in the direction of its initial motion. Calculate the time in which the electron would acquire a velocity double of its initial velocity.

MEDIUM

9th CBSE

IMPORTANT

NCERT Exemplar Science - Class 9>Chapter 8 - Motion>Long Answer Questions>Q 22

An electron moving with a velocity of

5 \times 10^{4} m s^{- 1}

enters into a uniform electric field and acquires a uniform acceleration of

10^{4} m s^{- 2}

in the direction of its initial motion. How much distance the electron would cover in this time?

HARD

9th CBSE

IMPORTANT

NCERT Exemplar Science - Class 9>Chapter 8 - Motion>Long Answer Questions>Q 23

Obtain a relation for the distance travelled by an object moving with a uniform acceleration in the interval between

4 t h

and

5 t h

seconds.

HARD

9th CBSE

IMPORTANT

NCERT Exemplar Science - Class 9>Chapter 8 - Motion>Long Answer Questions>Q 24

Two stones are thrown vertically upwards simultaneously with their initial velocities

u_{1}

and

u_{2}

respectively. Prove that the heights reached by them would be in the ratio of

{u_{1}}^{2} : {u_{2}}^{2}

(Assume upward acceleration is

- g

and downward acceleration to be

+ g

).

MEDIUM

9th CBSE

IMPORTANT

NCERT Exemplar Science - Class 9>Chapter 8 - Motion>Multiple Choice Questions>Q 1

Which of the following statement is not correct for an object moving along a straight path in an accelerated motion?