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

which three statements are true about all alloys?