Question

100kg car speed 20m/s to rest distance of 50 m.calculate(1)acceleration(2)unbalanced force

Answer 1

intial speed = u = 20m/s
final speed = v = 0m/s
distance = s = 50m

mass = m = 100kg

acceleration = a = ?

force = F = ?
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1)
v²-u² = 2as

v²-u²/2s = a

a = v²-u²/2s

a = (0)²-(20)²/2(50)

a = 0-400/100

a = -400/100

a = -4

a = 4 (because speed I'd scalar quantity means it has only magnitude not direction) .
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2)
Force = mass × acceleration

F = m × a

F = 100 × 4

F = 400N

so force = 400newton .
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