Q86 / 90 · JEE Main 2024 (04 Apr Shift 2) · Physics

A bus moving along a straight highway with speed of $72 \mathrm{~km} / \mathrm{h}$ is brought to halt within $4 s$ after applying the brakes. The distance travelled by the bus during this time (Assume the retardation is uniform) is _____m.

Correct answer: 40

Solution

$\begin{aligned} & \text { Initial velocity }=u=72 \mathrm{~km} / \mathrm{h}=20 \mathrm{~m} / \mathrm{s} \\ & \mathrm{v}=\mathrm{u}+\text { at } \\ & \Rightarrow 0=20+\mathrm{a} \times 4 \\ & \mathrm{a}=-5 \mathrm{~m} / \mathrm{s}^2 \\ & \mathrm{v}^2-\mathrm{u}^2=2 \text { as } \\ & \Rightarrow 0^2-20^2=2(-5) . \mathrm{s} \\ & \mathrm{s}=40 \mathrm{~m}\end{aligned}$

Hence, the correct answer is 40.

Relevant Questions

A paratrooper jumps from an aeroplane and opens a parachute after 2 s of free fall and starts deaccelerating with . At 10 m height from grou23 Jan, 2026 (E)Uniform Motion
Two cars and are moving on a road in the same direction. Acceleration of car increases linearly with time whereas car moves with a constant 29 Jan, 2025 (E)Uniform Motion
The relation between time ‘ t ’ and distance ‘ x ’ is t = α x 2 + β x , where α and β are constants. The relation between acceleration a and31 Jan, 2024 (M)Uniform Motion
A body starts moving from rest with constant acceleration covers displacement S 1 in first ( p - 1 ) seconds and S 2 in first p seconds. The29 Jan, 2024 (M)Uniform Motion
A bullet is fired into a fixed target looses one third of its velocity after travelling 4 cm . It penetrates further D × 10 - 3 m before com27 Jan, 2024 (E)Uniform Motion
A ball is thrown vertically upward with an initial velocity of 150 m s - 1 . The ratio of velocity after 3 s and 5 s is x + 1 x . The value 12 Apr, 2023 (M)Uniform Motion