The braking distance of a road train travelling at 15m/s is 70m. Assuming that the same braking force is applied at all speeds, show that the braking distance of a road train when travelling at 25m/s is about 190m.

Energy = force x distance and Energy = 0.5 x mass x velocity squared

Hence, force = (0.5 x mass x velocity squared) / distance --- (equation 1) This applies for both situation A and B, and given that force is stated to be the same in each case, and mass is the same, we can equate eqn 1 for each.

Hence, (0.5 x mass x velocity(A) squared) / distance(A) = (0.5 x mass x velocity(B) squared) / distance(B)

and so distance(B) = (velocity(B) squared x distance(A)) / (velocity(A) squared) = (25^2 x 70) / 15^2 = 194m

JJ
Answered by Jack J. Physics tutor

9578 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

A ball with radius 10cm is filled with an ideal gas at pressure 2*(10)^5Pa and temperature 300K. The volume of the gas is changed at constant pressure so that the radius of the ball is reduced with 1cm. Find the amount of gas and the new temperature


Describe how the strong nuclear force between two nucleons varies the distance between the 2 nucleons.


Define the term "Gravitational Potential" and write down a formula which defines it.


A car of mass m is travelling at a speed v around a circular track of radius r banked at an angle θ. (a) What is the centripetal acceleration of the car? (b) What is the normal force acting on the car? (c) If θ = 45°, r = 1 km what is the maximum speed?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences