A car running at a speed of 72 km/hr is slowed down to 18 km/hr over a distance of 40 - Science - Force and Laws of Motion

Question

A car running at a speed of 72 km/hr is slowed down to 18 km/hr
over a distance of 40 m Calculate: (1) retardation produced by its
brakes (2) time for which brakes are applied?

Sanjay Singh · Accepted Answer

Dear student
Initial velocity u=518×72=20m/sFinal velocity v=518×18=5m/sUsing the formula v2-u2=2as52-202=2a×4025-400=80aa=-37580=-7516=4
687m/s2Time to acquire the final velocity Using the formula v=u+at5=20-7516t-15=-7516tt=15×1675=165=3
2sRegards

A car running at a speed of 72 km/hr is slowed down to 18 km/hr over a distance of 40 m.Calculate: (1) retardation produced by its brakes (2) time for which brakes are applied?