# physics

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A car accelerates from rest at a steady rate of 1 ms-2. Calculate:
(a) the time taken to reach 15 ms-1
(b) the distance travelled during this time
(c) the velocity of the car when it was 100 m from the start point

• physics -

1.
For accelerated motion
s=v0t+(at2/2) and v=v0 + at
Since initial velocity v0 is zero,
s=at2/2 and v= at.
t=v/a=15/1=15 s.
s=1•225/2=112.5 m.
2.
If s =at2/2 = 100 m,
t=sqroot(2s/a)= sqroot(2•100/1)=14.14 s.
v=at=1•14.14=14.14 m/s.

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