The car needs to decelerate at a rate "a" such that sqrt(2aX) = V
a = V^2/(2 X)
To get the answer in m/s^2, you first need to convert the speed V to m/s and the distance X to meters.
He needs to brake to avoid breaking. Note the spelling of those different words.
A car is heading towards a brick wall at 80 km/hr, he starts breaking 30 feet away. What acceleration is required to avoid a collision?
2 answers
Vo=80,000m/h * (1/3600)h/s = 22.22m/s.
d = 30ft * (1/3.3)m/ft = 9.09m.
Vf^2 = Vo^2 + 2ad,
a = (Vf^2-Vo^2) / 2d,
a = (0-493.73) / 18.18 = - 27.2m/s^2.
d = 30ft * (1/3.3)m/ft = 9.09m.
Vf^2 = Vo^2 + 2ad,
a = (Vf^2-Vo^2) / 2d,
a = (0-493.73) / 18.18 = - 27.2m/s^2.
1 answer