Question

An advertisement claims that a particular automobile can "stop on a dime". What net force would be necessary to stop a 900 kg automobile traveling initially at 54.0 km/h in a distance equal to the diameter of a dime, 1.8 cm?

Answer 1

Force applied will be equal to 5625000 N

Step-by-step explanation:

We have given mass of the automobile m = 900 kg

Initial velocity of the automobile u = 54 km/hr

As 1 km = 1000 m and 1 hour = 3600 sec

So
`54km/hr=54* (5)/(18)=15m/sec`

As the automobile finally stops so final velocity v = 0 m/sec

Distance after which automobile stops s = 1.8 cm = 0.018 m

From third equation of motion
`v^2=u^2+2as`

`0^2=15^2+2* a* 0.018`

`a=-6250m/sec^2`

From newtons force on any object is equal to F = ma

So force
`F=900* 6250=5625000N`

So force applied will be equal to 5625000 N