When brakes are applied to a moving bus at 60km hr-1it retardation at a uniform rate of 5ms-2 caculate the time taken to reach a velocity of 35km hr-1
To calculate the time it takes for the bus to reach a velocity of 35 km/hr from an initial velocity of 60 km/hr, given a uniform retardation of 5 m/s², we can use the equations of motion.
First, we need to convert the velocities from km/hr to m/s, as the acceleration is given in m/s².
Initial velocity (u) = 60 km/hr = 60 * (1000m / 3600s) = 16.67 m/s
Final velocity (v) = 35 km/hr = 35 * (1000m / 3600s) = 9.72 m/s
Acceleration (a) = -5 m/s² (Negative because the acceleration is in the opposite direction to the motion)
We can use the equation of motion:
v = u + at
Rearranging the equation to solve for time (t):
t = (v - u) / a
Substituting the given values:
t = (9.72 - 16.67) / -5
t = -6.95 / -5
t = 1.39 seconds
Therefore, it will take approximately 1.39 seconds for the bus to reach a velocity of 35 km/hr.