A car with a total mass of 1400kg (including occupants), traveling at 60kmh^-1 hits a large tree and stops in 0.08seconds. What is the magnitude of the deceleration of the 70kg driver of the car if he is wearing a properly fitted seat belt?

Question

2291 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-05-06T08:52:50

$208.bar 3ms^-2$

Using the kinematic equation

$v=u+at$
where symbols have their respective meanings. Inserting given values in SI units, and assuming that deceleration is constant, we have

$0=(60xx10^3)/3600+axx0.08$
$0=>a=-(60xx10^3)/3600xx1/0.08=-208.bar 3ms^-2$
$-ve$ sign shows it is deceleration.

This is deceleration of car, its occupants including driver.