Third Equation of Motion

Q.

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

Q. A bus starting from rest moves with a uniform acceleration of $0.1m{s}^{-2}$ for $2minutes$. Find
(a) the speed acquired, (b) the distance travelled.

1. $10m{s}^{-1}$ , $700m$
2. $12m{s}^{-1}$ , $720m$
3. $12m{s}^{-1}$ , $700m$
4. $10m{s}^{-1}$ , $720m$

Q.

A bullet hits a wall with a velocity of 20m/s and penetrates it up to a distance of 5 cm. Find the deceleration of the bullet in the wall.

Q.

A scooter acquires a velocity of 36km/h in 10 seconds just after the start.calculate the acceleration of the car.

Q.

A car moving with velocity 54 km/h travelling on a straight road on applying brakes stops after covering 20 m. Find acceleration of the car

Q. A cyclist is traveling at 15m/sec. She applies brakes so that she does not collide with a wall 18 metre away. What deacceleration must she have?

Q.

A bicycle increases its velocity from 10km/h to 15km/h in 6 seconds. Calculate its acceleration.

Q.

Derive the 1st equation of motion.

Q. A body moving along a straight line at 20 metre per second undergoes and acceleration of 4 m/s²after 2 second is its speed will be

Q.

A stone is thrown vertically upward with an initial velocity of $40m{s}^{-1}$. Taking $g=10m{s}^{-2}$, find the maximum height reached by the stone. What is the net displacement and the total distance covered by the stone?

Q.

A bus moving with a velocity of 60 km/h is brought to rest in 20 sec by applying the brake, find acceleration.

Q.

A body is thrown vertically upwards with an initial velocity of 19.6 m/s. If accelaration due to gravity $g=9.8m/s^2$. Calculate the following:
(i) The maximum height attained by the body.
(ii) The time to reach the ground. [5 MARKS]

Q. Prove that, for a body thrown vertically upwards, the time of ascent is equal to the time of descent.

Q. Question 1
A bus starting from rest moves with a uniform acceleration of $0.1m{s}^{-2}$ for 2 minutes. Find
(a) the speed acquired, (b) the distance travelled.

Q.

Earth completes one revolution around the sun in 365 days. Calculate its angular velocity in $\frac{rad}{s}$. If the average distance from the sun is 150 million km, find Earth's linear velocity. [3 MARKS]

Q.

A car starts from rest . It moves with uniform acceleration. In 10sec it attains a speed of 72km/h on a straight road. Find its acceleration?

Q. Velocity and acceleration of a particle at some instant of time are v=3i+4j and a=-(6i+8j) respectively.At the same instant particle is at origin.Maximum x-coordinate of particle will be: 1.15m 2.0.75m 3.225 4.4m

Q.

A car starts from rest and accelerates uniformly at the rate of -1m/s¹ for 5sec. It the maintains rhe velocity for 30 s. then the brakes are applied and the car is retarded to rest in 10 s. Find the maximum velocity attained by the car and the total distance travelled by it.

Q.

A car moves linearly with uniform retardation. If the car covers 40m in the last 2 seconds of its motion, what is the velocity of the car at the beginning of the last second

Q.

A motor bike, initially moving at 18 km/h, accelerates at a rate of 5 m/s² for 5 sec. Calculate the distance covered by it from start.

Q.

A driver decreases the speed of a car from 25 m/s to 10 m/s in 5 seconds . Find the acceleration of the car.

Q.

A body when projected up with an initial velocity u goes to a maximum height h in time t and then comes back at the point of projection.The correct statement is:

(a) the average velocity is $\frac{2h}{t}$

(b) the acceleration is zero

(c) the final velocity on reaching the point of projection is 2u.

(d) the displacement is zero.

Q.

A van accelerates uniformly and its velocity changes from 5 m/s to 25 m/s in time t. Find its velocity.

Q. A train starting from rest position and moving with uniform acceleration attains a speed of 36km/hr in 10 min.find it's acceleration?

Q. A plane has take off speed of 88.1m/s and requires 1365m to reach that speed . Determine the acceleration of the plane and the time required to reach this speed.

Q. A car A of mass $1500kg$ is travelling at $25m{s}^{-1}$ collides with another car B of mass $1000kg$ travelling at $15m{s}^{-1}$ in the same direction. After collision, the velocity of car A reduces to $20m{s}^{-1}$. Calculate the velocity of car B after the collision.

1. $32.5m{s}^{-1}$
2. $35m{s}^{-1}$
3. $22.5m{s}^{-1}$
4. $25m{s}^{-1}$

Q.

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

Q.

A stone, thrown vertically upward from the surface of the moon at a velocity of $24\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$sec$}\right.$ reaches a height of $s=24t-0.8t^2$ metre after $t$ second. The acceleration due to gravity in $\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$se{c}^2$}\right.$ at the surface of the moon is

1. $0.8$

2. $-1.6$

3. $2.4$

4. $-4.9$

Q. A bullet train starts from rest, and acquires a speed of $25m{s}^{-1}$ in $20s$. Assuming uniform acceleration calculate the distance covered by the train in $20s$.

1. $1000m$
2. $100m$
3. $100km$
4. $10km$

Q.

A girl running in a race accelerates at $2.5m/s^2$ for the $4seconds$ of the race. How far does she travel in this time?