CLASS: IX NCERT (CBSE)

PHYSICS

Motion

Question 1: 1 km/h = _____ m/s

1.

2.

3.

4.

Answer: 1

Question 2: The distance (s) in metres travelled by a particle is related to time (t) in seconds by the equation of motion -S = 10t + 4t2. What is the initial velocity of the body?

1. 10 m/s

2. 6 m/s

3. 4 m/s

4. 10 m/s2

Answer: 1

Question 3: For the equation – S = 10t + 4t2 what is the acceleration of the body?

1. 8 m/s2

2. 10 m/s2

3. 4 m/s2

4. 8 m/s

Answer: 1

Question 4: A body moving along a straight line at 20 m/s decelerates at the rate of 4 m/s2. After 2 seconds its speed will be equal to

1. 8 m/s

2. 12 m/s

3. 16 m/s

4. – 12 m/s

Answer: 2

Question 5: Give the equation of motion connecting u, v, a and s where the symbols have their usual meaning

1. v = u + at

2.

3. v2 – u2 = 2aS

4.

Answer: 3

Question 6: An object moving with a speed of 5 m/s comes to rest in 10 s, after the brakes are applied. What is the initial velocity?

1. zero

2. 5 m/s

3. 15 m/s

4. 50 m/s

Answer: 2

Question 7: A body moving along a straight line at 40 m/s undergoes an acceleration of 4 m/s2. After 10 seconds its speed will be

1. 20 m/s

2. 28 m/s

3. 16 m/s

4. 80 m/s

Answer: 4

Question 8: SI unit of acceleration is __________.

1.

2.

3.

4.

Answer: 1

Question 9: Retardation is __________.

1. negative acceleration

2. positive acceleration

3. uniform acceleration

4. variable acceleration

Answer: 1

Question 10: When an object is moving with uniform velocity, what is its acceleration?

1. zero

2. uniform

3. non-uniform

4. negative

Answer: 1

Question 11: In the case of a rectilinear uniform motion, distance-time graph is a

1. parabola

2. straight line

3. curved line

4. rectangle

Answer: 2

Question 12: Speed of 90 km/h when expressed in m/s is .

1. 2.5

2. 25

3. 250

4. 90000

Answer: 2

Question 13: When a graph of one quantity versus another results in a straight line, the quantities are

1. directly proportional

2. constant

3. inversely proportional

4. independent of each other

Answer: 1

Question 14: What does the following S-t graph indicate?

1. uniform speed

2. body is at rest

3. non-uniform speed

4. variable speed

Answer: 2

Question 15: What do you infer, if S-t graphs of two cyclists meet at a point?

1. They collide

2. They pass each other

3. They are at rest

4. They are starting from rest

Answer: 2

Question 16: Name the physical quantity which we get from a S-t graph.

1. Speed

2. Displacement

3. Distance

4. Time

Answer: 1

Question 17: What is the SI unit of speed?

1. km/h

2. m/s

3. m/min

4. km/s

Answer: 2

Question 18: What is the distance covered by a car in 5 h if it is moving with a speed of 35 km/h?

1. 175 km

2. 150 km

3. 7 km

4. 1750 km

Answer: 1

Question 20: The average speed of a car which covers half the distance with a speed of 20 m/s and other half with a speed of 30 m/s in equal intervals of time is _________.

1. 25 m/s

2. 0 m/s

3. 24 m/s

4. 2.4 m/s

Answer: 1

Question 21: Displacement is a ________ quantity.

1. scalar

2. vector

3. derived

4. linear

Answer: 2

Question 22: km / h2 is a unit of ________ .

1. velocity

2. speed

3. acceleration

4. distance

Answer: 3

Question 23: The speed-time graph for a particle moving at constant speed is a straight-line ________ to the time axis.

1. parallel

2. perpendicular

3. aligned

4. inclined

Answer: 1

Question 24: When an object moves in a fixed direction with uniform acceleration, the speed-time graph is a ________.

1. parabola

2. straight line

3. ellipse

4. curve

Answer: 2

Question 25: The area under the speed-time graph gives the ________.

1. distance

2. velocity

3. time

4. acceleration

Answer: 1

Question 26: A speed of 90 km/h, expressed in cm s-1 is ________.

1. 2.5

2. 2500

3. 300

4. 90

Answer: 2

Question 27: When an object of mass 5 kg starts from rest, what is its initial velocity?

1. 0

2. – 5 m/s

3. variable

5

4. 1 m/s

Answer: 1

Question 29: Name the physical quantity that is defined as the rate of change of displacement.

1. velocity

2. acceleration

3. distance

4. speed

Answer: 1

Question 30: An object moves with a constant velocity of 9.8 m/s, its acceleration in m s-2 is ________.

1. 9.8 m/s2

2. zero

3. 0.98 m/s

4. 98 m/s2

Answer: 2

Question 31: In 12 minutes a car whose speed is 35 km/h travels a distance of

1. 7 km

2. 3.5 km

3. 14 km

4. 28 km

Answer: 1

Question 32: A body moving along a straight line at 20 m/s undergoes an acceleration of 4 m/s2. After two seconds its speed will be ________.

1. 8 m/s

2. 12 m/s

3. 16 m/s

4. 28 m/s

Answer: 4

Question 33: A car increases its speed from 20 km/h to 50 km/h in 10 seconds. Its acceleration is ________.

1. 30 m/s2

2. 3 m/s2

3. 18 m/s2

4. 0.83 m/s2

Answer: 4

Question 34: When the distance covered by an object is directly proportional to time, it is said to travel with ________.

1. zero velocity

2. constant speed

3. constant acceleration

4. uniform acceleration

Answer: 2

Question 35: Negative acceleration means an object is moving with ________.

1. increasing speed

2. decreasing speed

3. uniform speed

4. constant speed

Answer: 2

Question 36: Motion along a straight line is called __________ motion.

1. rectilinear motion

2. circular motion

3. oscillatory motion

4. parabolic

Answer: 1

Question 37: Distance-time graph is a straight line for __________ motion.

1. variable

2. non uniform

3. rectilinear

4. circular

Answer: 3

Question 38: A car is moving with a speed of 36 km/h. Its speed in m/s is _______.

1. 10

2. 100

3. 2

4. 1

Answer: 1

Question 39: A car starts from rest and covers a distance of 100 m in one second with uniform acceleration. Its acceleration is _________.

1. 100 m/s2

2. 50 m/s2

3. 200 m/s2

4. 100 m/s

Answer: 1

Question 40: Which of the following is a vector quantity?

1. area

2. length

3. distance

4. displacement

Answer: 4

Question 41: The slope of a v-t graph gives ________.

1. acceleration

2. velocity

3. speed

4. distance

Answer: 3

Question 42: The physical quantity describing motion and whose measure is the product of distance travelled and the time taken to travel that distance is ________.

1. speed

2. mass

3. weight

4. displacement

Answer: 1

Question 43: If you are travelling with a velocity of 25 m/s, how long will you take to travel 700 m?

1. 25 s

2. 28 s

3. 25 min

4. 2.8 s

Answer: 2

Question 44: Name the instrument used to measure instantaneous speed of a vehicle.

1. accelerator

2. speedometer

3. ammeter

4. multimeter

Answer: 2

Question 45: A body covers a distance S in time t. What is its speed?

1. S/t

2. t/S

3. S x t

4. Zero

Answer: 1