You are driving at 35.8 m/s when you see a roadblock 100 meters ahead. If you break at a safe deceleration rate of about -4.5m/s^2, how fast will you be going when you reach the roadblock?
brake.
Use the kinematics equation
v2²-v1²=2aS
v2=final velocity
v1=initial velocity
S=distance travelled
a=uniform acceleration.
I get approximately 20 m/s if I assume you mean deceleration of 4.5m/s or acceleration of -4.5 m/s.
Deceleration of -4.5 m/s will actually accelerate.