A car accelerates uniformly from rest at 4 ms\(^{-2}\). How far will it travel in the fifth complete second?

Knowledge_OA

2 years ago

when you see a question that needs you to calculate using "nth" second, the "nth second" given - its previous second all divided by 2 is the way to go about it. i.e "5th" second = (5sec - 4sec)/2.....we all know that acceleration(a) = displacement(d)/time²(t²)...(acceleration is the second derivative of displacement), therefore d = at²...so since the time is squared now, it will obviously be [("nth" second)² - (previous second)²]/2.
from the question above we're told to find d in the 5th second, given that a = 4m/s².
we already know that d = at².
so d = 4 * (5² - 4²)/2
d = 4 * (25 - 16)/2
d = 4 * (9)/2
d = 4 * 4.5
d = 18m (Option D)

profit690

4 years ago

a=4,t= u=0,s=?
s=u+1/2at^2
s=1/2x4[5^2+4^2]
s=0.5x4x9
s=18

Prof E.C.G

12 years ago

here is d simplest method....(a-0.5)T=(4-0.5)*5=17.5m approximately 18m

Suliah

3 years ago

Thanks for the explanation

mikel_1

3 years ago

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