A car is traveling at 80 miles per hour down a paved, asphalt road in good condition. The driver steps on the brake, decelerating at a constant rate (expressed in m/s^2), to avoid hitting a horse in the road 1500 feet away. If the driver does not wish to experience too rapid a deceleration, in other words, a deceleration greater than -2g’s or -2 x 9.8 m/s^2 to avoid skidding or possible bodily injury, and is only able to decelerate in a straight line, how long does it take the driver to stop? Can a collision with the horse be avoided? Note: Convert all variables to the metric (mks) system before performing your calculations.

3 answers

vf^2=vi^2+2ad
1500ft=457m
80mph=35.7m/s

0^2=35.7^2+2a(457) solve for a. Is it less than 2g?
So it would be ....
0=1274.49+2a(457)
O=1274.49+914a?
Yes? No?