4. A train is travelling at a speed of 60 km / h. Brakes are applied so as to produce a uniform

acceleration of - 0.5 m / s2

. Find how far the train will go before it is brought to rest.

33.33 m

Explanation:

Applying Newton's equation of motion,

v² = u²+2as ... Equation 1

Where v = final velocity of the train, u = initial velocity of the train, a = acceleration of the train, s = distance.

make s the subject of the equation

s = (v²-u²) / 2a ... Equation 2

Given: v = 0 m/s (brought to rest), u = 60 km/h = 60 (1000/3600) m/s = 16.67 m/s, a = - 0.5 m/s²

Substitute this values into equation 2

s = (0-16.67) / -0.5

s = - 16.67/-0.5

s = 33.33 m