The graph given below shows the speed of a car changing with time: What is the initial speed of the car?

Initial speed of a body is defined as the speed of the car at 0 s . Here the value of speed at time, t = 0 h is 10 kmh - 1 Hence the initial speed of the car is 10 kmh - 1 .

The graph given below shows the speed of a car changing with time: What is the maximum speed attained by the car?

The maximum speed is the highest value of velocity ( Y - a x i s ) in a V - t graph. In the given graph, the maximum value observed is 35 kmh - 1 . Hence the maximum velocity of the car is 35 kmh - 1

The graph given below shows the speed of a car changing with time: Which part of the graph shows zero acceleration?

Acceleration is defined as rate of change of velocity. So, acceleration is zero when velocity is constant. In graph from point B to point C velocity is same ( 35 kmh - 1 ) . Hence the part B C of the graph shows zero acceleration.

The graph given below shows the speed of a car changing with time: Which part of the graph shows varying retardation?

No part of the graph shows varying retardation. Retardation is nothing but a negative acceleration. If the velocity of the body increases, acceleration is said to be positive. If it decreases, acceleration is said to be negative and commonly called retardation. In the graph, the part from C to D has velocity as decreasing. Hence acceleration is negative (retardation). We also observe that magnitude of slope of line C D is a constant. Hence retardation is uniform.

The graph given below shows the speed of a car changing with time: Find the distance travelled in the first eight hours.

The distance travelled by the car from a V - t graph can be found by calculating the area under the curve. We should find the area of the shape O A B C E from the figure Let us divide the areas into 3 parts △ A G C , □ O A G F and □ B C E F Let area of the △ A G C be a 1 , a 1 = 1 2 A G B G ⇒ a 1 = 1 2 ( 3 ) ( 25 ) = 37 . 5 km . . . . . ( 1 ) Let the area of the □ O A G F be a 2 , a 2 = ( O A ) ( A F ) ⇒ a 2 = ( 3 ) ( 10 ) = 30 km . . . . . ( 2 ) Let the area of □ B C E F be a 3 , a 3 = ( F E ) ( F B ) ⇒ a 3 = ( 5 ) ( 35 ) = 175 km . . . . . ( 3 ) Hence total area, a = a 1 + a 2 + a 3 , From equations ( 1 ) , ( 2 ) and ( 3 ) we get, a = 37 . 5 + 30 + 175 ⇒ a = 242 . 5 km Therefore the total distance travelled by the car in eight hours is 242 . 5 km .

E M B I B E

Essentials of PHYSICS Class IX>Chapter 10 - Sample Paper 5>Sample Paper>Q 7

EASY

9th CBSE

IMPORTANT

Earn 100

What is momentum? Write its S.I. unit. Interpret force in terms of momentum. Represent the following graphically:

momentum versus velocity when mass is fixed.

Important Questions on Sample Paper 5

EASY

9th CBSE

IMPORTANT

Essentials of PHYSICS Class IX>Chapter 10 - Sample Paper 5>Sample Paper>Q 7

What is momentum? Write its S.I. unit. Interpret force in terms of momentum. Represent the following graphically:

momentum versus mass when velocity is constant.

EASY

9th CBSE

IMPORTANT

Essentials of PHYSICS Class IX>Chapter 10 - Sample Paper 5>Sample Paper>Q 8

How is ultrasound used in cleaning?

EASY

9th CBSE

IMPORTANT

Essentials of PHYSICS Class IX>Chapter 10 - Sample Paper 5>Sample Paper>Q 9

The graph given below shows the speed of a car changing with time:

Question Image

What is the initial speed of the car?

EASY

9th CBSE

IMPORTANT

Essentials of PHYSICS Class IX>Chapter 10 - Sample Paper 5>Sample Paper>Q 9

The graph given below shows the speed of a car changing with time:

Question Image

What is the maximum speed attained by the car?

EASY

9th CBSE

IMPORTANT

Essentials of PHYSICS Class IX>Chapter 10 - Sample Paper 5>Sample Paper>Q 9

The graph given below shows the speed of a car changing with time:

Question Image

Which part of the graph shows zero acceleration?

EASY

9th CBSE

IMPORTANT

Essentials of PHYSICS Class IX>Chapter 10 - Sample Paper 5>Sample Paper>Q 9

The graph given below shows the speed of a car changing with time:

Question Image

Which part of the graph shows varying retardation?

EASY

9th CBSE

IMPORTANT

Essentials of PHYSICS Class IX>Chapter 10 - Sample Paper 5>Sample Paper>Q 9

The graph given below shows the speed of a car changing with time:

Question Image

Find the distance travelled in the first eight hours.

EASY

9th CBSE

IMPORTANT

Essentials of PHYSICS Class IX>Chapter 10 - Sample Paper 5>Sample Paper>Q 10

A student measured the minimum force

F_{1}

to just move a rectangular wooden block kept with the largest surface area on a horizontal surface by a spring balance. He again measured the minimum force by placing the block with the smallest surface area on the table as