If a bus travelling at $20\ m/s$ is subjected to a steady deceleration of $5\ m/s^2$, how long will it take to come to rest ?

Academic Physics NCERT Class 9

Here given, initial velocity $u=20\ m/s$

Deceleration $a=-5\ m/s^2$ [Here $a$ will be negative]

Final velocity $v=0$ [Because the object will come to the rest]

On using the equation of motion $v=u+at$

$0=20+( -5)t$

Or $5t=20$

Or $t=\frac{20}{5}$

Or $t=4\ sec.$

Tutorialspoint

Simply Easy Learning

Updated on: 10-Oct-2022

96 Views

When a car driver travelling at a speed of $10\ m/s$ applies brakes and brings the car to rest in $20\ s$, then retardation will be:(a) $+2\ m/s^2$(b) $-2\ m/s^2$(c) $-0.5\ m/s^2$(d) $+0.5\ m/s^2$
A motorcycle is being driven at a speed of $20\ m/s$ when brakes are applied to bring it to rest in five seconds. The deceleration produced in this case will be:(a).\ +4\ m/s^2$(b).\ -4\ m/s^2$(c).\ +0.25\ m/s^2$(d).\ -0.25\ m/s^2$
How long will it take a force of 10 N to stop a mass of 2.5 kg which is moving at 20 m/s?
A bus moving along a straight line at $20\ m/s$ undergoes an acceleration of $4\ m/s^2$. After 2 seconds, its speed will be:(a) $8\ m/s$(b) $12\ m/s$(c) $16\ m/s$(d) $28\ m/s$
A car is moving along a straight road at a steady speed. It travels 150 m in 5 seconds. How long does it take to travel 240 m ?
A stone is thrown vertically upwards with a speed of 20 m/s. How high will it go before it begins to fall? $(g=9.8\ m/s^2)$
A stone is dropped from a height of 20 m.(i) How long will it take to reach the ground?(ii) What will be its speed when it hits the ground? $(g=10\ m/s^2)$
A bus increases its speed from $36\ km/h$ to $72\ km/h$ in $10\ seconds$. Its acceleration is:(a) $5\ m/s^2$(b) $2\ m/s^2$(c) $3.6\ m/s^2$(d) $1\ m/s^2$
A boy of mass 50 kg running at 5 m/s jumps on to a 20 kg trolley travelling in the same direction at 1.5 m/s. What is their common velocity?
An object travels $20\ m$ in $5\ s$ and then another $40\ m$ in $5\ s$. What is the average speed of the object?$6\ m/s$$0\ m/s$$12\ m/s$$2\ m/s$
A man is \( 45 \mathrm{~m} \) behind the bus when the bus start accelerating from rest with acceleration 2.5 \( m / s^{2} \). With what minimum velocity should the man start running to catch the bus.(a) \( 12 \mathrm{~m} / \mathrm{s} \)(b) \( 14 \mathrm{~m} / \mathrm{s} \)(c) \( 15 \mathrm{~m} / \mathrm{s} \)(d) \( 16 \mathrm{~m} / \mathrm{s} \)
A train travels $100\ m$ long moving on a straight level track passes a pole in $5\ s$. Find the time it will take to cross a bridge $500\m$ long.
A bus travels 54 km in 90 minutes. The speed of the bus is$(a)$. 0.6 m/s$(b)$. 10 m/s$(c)$. 5.4 m/s$(d)$. 3.6 m/s
What is the momentum in kg.m/s of a 10 kg car travelling at (a) 5 m/s (b) 20 cm/s, and (c) 36 km/h ?
A car is travelling at a speed of $90\ km/h$. Brakes are applied so as to produce a uniform acceleration of $0.5 m/s^2$. Find how far the car will go before it is brought to rest?a). 8100 m b). 900 mc). 625 m d). 620 m

Kickstart Your Career

Get certified by completing the course

Get Started

Advertisements