Acceleration

Q.

The rate of change of velocity is called __

Q.

Why is acceleration a vector quantity?

Q. If a body starting from rest travels with a uniform acceleration of 10 ms-2 for first 10 second and with uniform acceleration 5 ms-2 for next 20 seconds, then average acceleration of the body for 30 s is

Q. Which of the following is true for displacement?
(a) It cannot be zero.
(b) Its magnitude is greater than the distance travelled by the object.

1. a only
2. b and c
3. All a, b and c
4. c only

Q.

A bus decreases its speed from 80 km/hr to 60 km/hr in 5 s. Find the acceleration of the bus.

1. $-2.22m/s^2$

2. $2.11m/s^2$

3. $-1.11m/s^2$

4. $0m/s^2$

Q.

What is erratic motion?

Q.

Acceleration is defined as the rate of change of________

Q. The decrease in velocity per unit time is called

1. acceleration
2. retardation
3. average velocity

Q.

Define acceleration and write its S.I unit.

Q.

Acceleration is defined as the rate of change of velocity.

1. True

2. False

Q.

$km/h^2$ is a unit of

1. velocity

2. acceleration

3. distance

4. displacement

Q.

The SI unit of acceleration is _________.

Q.

What is the acceleration of a car that starts from rest and attains a speed of $20m{s}^{-1}$ in 25 seconds?

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

2. $0.8m{s}^{-2}$

3. $0.7m{s}^{-2}$

4. $4m{s}^{-2}$

Q.

A car starting from rest acquires a velocity of 36 $\frac{km}{h}$ in 5 s .Calculate

(a) its acceleration .

(b) the distance covered by it .

Q.

A particle with one dimensional motion with positive value of acceleration must be speeding up.

1. True
2. False

Q. A car of mass $1000kg$ is moving at a speed of $20m{s}^{-1}$. It is brought to rest at a distance of $50m$. Calculate the net force acting on the car.

1. $4000N$
2. $3000N$
3. $2000N$
4. $1000N$

Q.

Acceleration of a body can never be negative.

1. True

2. False

Q.

Name a physical quantity which corresponds to rate of change of velocity?

Q. Why is the operation of limit(delta t--0)of quantity used to calculate the instantaneous velocity?

Q.

A lift is descending with a constant velocity 'v'. A man in the lift drops a coin.The coin experiences an acceleration towards the floor equal to:

1. g + v

2. g - v

3. g

4. Zero

Q.

A constant force acts on a body of mass $m$ at rest. The velocity $v$ acquired in traversing a specific distance depends on $m$ as

1. $v\propto \frac{1}{m}$

2. $v\propto \frac{1}{\sqrt{m}}$

3. $v\propto m$

4. $v\propto \sqrt{m}$

Q.

If a car is moving northwards and the driver jams on its brakes, the direction of its acceleration is ____.

Q.

An object at rest starts moving and attains a velocity of $10m{s}^{-1}$ after 5 s. What is the acceleration?

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

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

3. $3m{s}^{-2}$

4. $4m{s}^{-2}$

Q. If a body is moving with uniform velocity in a given direction its acceleration will be zero. Why?

Q.

Why the acceleration is negative?

Q.

An object moving with a uniform velocity of $40m{s}^{-1}$ comes to rest in $10s$. What is the acceleration?

1. $-4m{s}^{-2}$

2. $4m{s}^{-2}$

3. $-10m{s}^{-2}$

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

Q.

What does area under v-t graph represents

1. displacement

2. Speed

3. distance

4. Acceleration

Q.

A car decreases its speed from 80 km/hr to 60 km/hr in 5 seconds. The acceleration of the car is :

1. -1.11 m/s²

2. 1.12 m/s²

3. -1.14 m/s²

4. 1.11 m/s²

Q.

The unit of acceleration in SI system is

1. $m$

2. $m/s$

3. $m/s^2$

4. $ms$

Q.

Acceleration is defined as the rate of change in velocity. Suppose we call the rate of change of acceleration ‘SLAP’. What is the unit of ‘SLAP’?