Flash Education

Question

A train moving with a velocity of 20 m s-1 is brought to rest by applying brakes in 5 s. Calculate the retardation.

Motion in One Dimension ICSE

February 27, 2024

Answer

According to equation of motion

v = u + at

Given,

u = 20 m s^-1,

v = 0,

t = 5 s

Substituting the values in the formula above, we get,

0 = 20 + a × 5

or, 0 = 20 + 5a

or, 5a = – 20

or, a = -20/5 = -4 m s^-2

Hence, Retardation is 4 m s^-2

Was this answer helpful?

Didn't liked the above answer ?

Text Generation Tool

💡 Some Related Questions

motion

A train starts from rest and accelerates uniformly at a rate of 2 m s-2 for 10 s. It then maintains a constant speed for 200 s. The brakes are then applied and the train is uniformly retarded and comes to rest in 50 s. Find — (i) the maximum velocity reached, (ii) the retardation in the last 50 s, (iii) the total distance travelled, and (iv)the average velocity of the train.

motion

A space craft flying in a straight course with a velocity of 75 km s-1 fires its rocket motors for 6.0 s. At the end of this time, its speed is 120 km s-1 in the same direction. Find – (i) the space craft’s average acceleration while the motors were firing (ii) the distance travelled by the space craft in the first 10 s after the rocket motors were started, the motors having been in action for only 6.0 s.

motion

A car travels with a uniform velocity of 25 m s-1 for 5 s. The brakes are then applied and the car is uniformly retarded and comes to rest in further 10 s. Find — (i) the distance which the car travels before the brakes are applied, (ii) the retardation and (iii) the distance travelled by the car after applying the brakes.

motion

A body moving with a constant acceleration travels the distances 3 m and 8 m respectively in 1 s and 2 s. Calculate — (i) the initial velocity, and (ii) the acceleration of body.

motion

A body moves from rest with a uniform acceleration and travels 270 m in 3 s. Find the velocity of the body at 10 s after the start.

motion

When brakes are applied to a bus, the retardation produced is 25 cm s-2 and the bus takes 20 s to stop. Calculate – (i) the initial velocity of bus, and (ii) the distance travelled by bus during this time.

motion

A car travels a distance 100 m with a constant acceleration and average velocity of 20 m s-1. The final velocity acquired by the car is 25 m s-1. Find: (i) the initial velocity and (ii) acceleration of car.

motion

A train is moving with a velocity of 90 km h-1. It is brought to stop by applying the brakes which produce a retardation of 0.5 m s-2. Find (i) the velocity after 10 s, and (ii) the time taken by the train to come to rest.

motion

A train travels at a speed of 60 km h-1 from station A to station B and then comes back at a speed of 80 km h-1 from station B to station A. Find — (i) the average speed, and (ii) the average velocity of the train.

motion

A bullet initially moving with a velocity 20 m s-1 strikes a target and comes to rest after penetrating a distance 10 cm in the target. Calculate the retardation caused by the target.

error: Content is protected !! 💀