A bus increases its speed from 36 km h to 72 km h in 10 seconds. What is its acceleration?

We know from the question that, Initial velocity of the bus, u = 36 km h = 36 × 5 18 = 10 m s . Final velocity of the bus, v = 72 km h = 72 × 5 18 = 20 m s . Time taken by the bus, t = 10 s . From the definition, We know that acceleration is the rate of change of velocity. ∴ a = v - u t ⇒ a = 20 - 10 10 = 1 m s 2

A scooter acquires a velocity of 36 km h in 5 s just after the start. Calculate the acceleration of the scooter.

We know from the question that, Initial velocity of the scooter, u = 0 Final velocity of the scooter, v = 36 km h = 36 × 5 18 = 10 m s . Time taken by the scooter, t = 5 s . From the definition of acceleration, we know that it is the rate of change of velocity. ∴ a = v - u t ⇒ a = 10 - 0 5 ⇒ a = 2 s

A bus travelling at 30 km h speeds up to 60 km h in 6 seconds. What is its acceleration in m s 2 ?

We know from the question that, Initial velocity of the bus, u = 30 km h = 30 × 5 18 = 50 6 m s Final velocity of the bus, v = 60 km h = 60 × 5 18 = 100 6 m s Time taken by the bus, t = 6 s From the definition, acceleration is the rate of change of velocity. ∴ a = v - u t ⇒ a = 100 6 - 50 6 6 ⇒ a = 50 36 = 1 . 389 m s 2

Describe the motion of a body which is accelerating at a constant rate of 10 m s 2 . If the body starts from rest, how much distance will it cover in 2 s.

We know from the question, Initial velocity of the body, u = 0 Acceleration of the body, a = 10 m s 2 Time taken by the body to cover the distance required, t = 2 s Considering the variables given, we can safely say that this uniformly accelerated motion. This is because the acceleration of the body is constant. To find the distance, we use the second equation of motion. s = u t + 1 2 a t 2 Substituting the values in this equation, we get, ∴ s = 0 × 2 + 0 . 5 × 10 × 4 ⇒ s = 20 m

E M B I B E

Essentials of PHYSICS Class IX>Chapter 1 - Motion>Practice Problems

Priyanka B Solutions for Chapter: Motion, Exercise 4: Practice Problems

Author:Priyanka B

Priyanka B Physics Solutions for Exercise - Priyanka B Solutions for Chapter: Motion, Exercise 4: Practice Problems

Attempt the free practice questions on Chapter 1: Motion, Exercise 4: Practice Problems with hints and solutions to strengthen your understanding. Essentials of PHYSICS Class IX solutions are prepared by Experienced Embibe Experts.

Questions from Priyanka B Solutions for Chapter: Motion, Exercise 4: Practice Problems with Hints & Solutions

EASY

9th CBSE

IMPORTANT

Essentials of PHYSICS Class IX>Chapter 1 - Motion>Practice Problems>Q 8

An aeroplane taking off from a field has a run of $500 m$ . What is the acceleration, if it leaves the ground in $10 s$ .

EASY

9th CBSE

IMPORTANT

Essentials of PHYSICS Class IX>Chapter 1 - Motion>Practice Problems>Q 9

A train starting from stationary position and moving with uniform acceleration attains a speed of $36 \frac{km}{h}$ in $10 minutes$ . Find its acceleration.

EASY

9th CBSE

IMPORTANT

Essentials of PHYSICS Class IX>Chapter 1 - Motion>Practice Problems>Q 10

A bus increases its speed from $36 \frac{km}{h}$ to $72 \frac{km}{h}$ in $10$ seconds. What is its acceleration?

EASY

9th CBSE

IMPORTANT

Essentials of PHYSICS Class IX>Chapter 1 - Motion>Practice Problems>Q 11

A scooter acquires a velocity of $36 \frac{km}{h}$ in $5 s$ just after the start. Calculate the acceleration of the scooter.

EASY

9th CBSE

IMPORTANT

Essentials of PHYSICS Class IX>Chapter 1 - Motion>Practice Problems>Q 12

A bus travelling at $30 \frac{km}{h}$ speeds up to $60 \frac{km}{h}$ in $6$ seconds. What is its acceleration in $\frac{m}{s^{2}}$ ?

EASY

9th CBSE

IMPORTANT

Essentials of PHYSICS Class IX>Chapter 1 - Motion>Practice Problems>Q 13

Describe the motion of a body which is accelerating at a constant rate of $10 \frac{m}{s^{2}}$ . If the body starts from rest, how much distance will it cover in $2$ s.

EASY

9th CBSE

IMPORTANT

Essentials of PHYSICS Class IX>Chapter 1 - Motion>Practice Problems>Q 14

Find the initial velocity of a car which is stopped in $10$ seconds by applying brakes. The retardation due to brakes is $2.5 \frac{m}{s^{2}}$ .

MEDIUM

9th CBSE

IMPORTANT

Essentials of PHYSICS Class IX>Chapter 1 - Motion>Practice Problems>Q 15

A body starting from rest travels with uniform acceleration. If it travels $100 m$ in $5 s$ , what is the value of the acceleration?