J Jerry Member Oct 9, 2011 #1 horizontal roadway.? When its brakes are applied, the car stops in 6.9 s. What is the average horizontal force exerted on the car while it is braking?
horizontal roadway.? When its brakes are applied, the car stops in 6.9 s. What is the average horizontal force exerted on the car while it is braking?
T tes2 New member Oct 23, 2011 #2 u = 21m/s v = 0m/s t = 6.9s a = ? v = u + at -> a = (v-u)/t = -21/6.9 = -3.043m/s F = ma = 1300*(-3.043) = -3956.5N So 4000N west (two significant figures)
u = 21m/s v = 0m/s t = 6.9s a = ? v = u + at -> a = (v-u)/t = -21/6.9 = -3.043m/s F = ma = 1300*(-3.043) = -3956.5N So 4000N west (two significant figures)