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

Answer:

Force applied will be equal to 5625000 N

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 $54km/hr=54\times \frac{5}{18}=15m/sec$

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 $v^2=u^2+2as$

$0^2=15^2+2\times a\times 0.018$

$a=-6250m/sec^2$

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

So force $F=900\times 6250=5625000N$

So force applied will be equal to 5625000 N