How much work is needed to stop a 1100 kg car at 118 km/h?

lim · Nov 13, 2007

Homework Statement

How much work must be done to stop a 1100 kg car traveling at 118 km/hr?

Ei + W= Ef
KE= 1/2mv^2

KE= 1/2mv^2

118kmx1000m/360s= 327.78

327.78^2= 107437.76

107437.76x1100= 118181537.9

118181537.9/2 = -5.91x10^7

thanks for any help

Doc Al · Nov 13, 2007

lim said:

118kmx1000m/360s= 327.78

Recheck that conversion: How many seconds in an hour?

alexwaylo2008 · Nov 13, 2007

do KE = 1/2 (1100 kg)(118*(1000/3600))^2