Answer: C, 0.9g
We know that 1 g = 9.8 m/s^2. So first we’ll need to convert 100 km/hr to m/s. So we can compare meters to meters and seconds to seconds (we’ll handle the s^2 soon).
100 km/hr * (1000 m)/(1 km) * (60 min)/(1 hr) * (60 sec)/(1 min) = 27.778 m/s.
We know that this car achieved this speed in 3 seconds. Since acceleration is change in velocity, and we know the velocity of the car changed from 0 to about 27.8 m/s in 3 seconds, we know that our acceleration is:
(27.8 m/s - 0 m/s) / (3 s) = 9.259 m/s^2.
Now to find how many g’s, we know that 1 g = 9.8 m/s^2. So we know that 9.259 m/s^2 / 9.8 m/s^2 = about 0.9. This will be 0.9 of 1 g, which is just 0.9 g.
