Monday

January 26, 2015

January 26, 2015

Posted by **Kaylee** on Tuesday, June 24, 2014 at 10:24pm.

The acceleration of gravity is 9.8 m/s2 .

What is the magnitude of the work done stopping the car if the car just stops in time to avoid diving into the water?

Answer in units of J

- physics -
**MathMate**, Wednesday, June 25, 2014 at 7:08amUsing Newton's second law F=ma

to find the mass, then again the same law to find the frictional force.

Finally use Work done = F.D

Units are in kg, m/s² and J.

Mass m = 7750/9.8 = 790.82 kg

Frictional force = ma

= 790.82 kg * 10.6 m/s²

= 8382.7 N

Work done (assuming uniform frictional foce)

= F.D

= 8382.7 N * 28.5 m

= 238906 J

= 238.9 kJ

**Answer this Question**

**Related Questions**

PHYSICS - A driver of a 7400 N car passes a sign stating "Bridge Out 30 Meters ...

physics - A driver of a 7550 N car passes a sign stating "Bridge Out 25 Meters ...

physics - A driver of a 7550 N car passes a sign stating "Bridge Out 25 Meters ...

physics - A driver of a 7550 N car passes a sign stating "Bridge Out 25 Meters ...

physics - A driver of a 7100 N car passes a sign stating "Bridge Out 30 Meters ...

physics - A driver of a 7.50 N car passes a sign stating "Bridge Out 30 Meters ...

Physics - The speed limit in a school zone is 40 km/h. A driver traveling at ...

Physics - A car with mass of 1875kg is traveling along a country road when the ...

physics - The speed limit in a school zone is 38 km/h. A driver traveling at ...

Physics - Problem 4- Speedy car, driving at 30 m/s. The driver suddenly ...