A body travels 200 cm in the first 2 s and 220 cm in the next 5 s. Calculate the velocity at the end of the seventh second from the start. (Ans. 2.22 m/s)
PLS DO A SOLUTION.
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Answer:
The body seems to decelerate, so the velocity should be less than 1 after 7 sec. , please check if Ans. is 2.22 or not.
Here is what I think
Explanation:
s1 = 200 cm = 2 m
t1 = 2 sec.
therefore, u = 2/2 = 1 m/s
s2 = 220 cm = 2.2 m
t2 = 5 sec.
therefore, v = 2.2/5 = 0.44 m/s
now, a = (v - u) ÷ t
= (0.44 - 1) ÷ (5 - 2)
= -0.66 ÷ 3 = -0.22 m/s^2
since a = -0.22 m/s^2
therefore, by 1st equation of motion
v = u + a.t
= 0.44 + (-0.22)×(5-7)
= 0.44 - 0.44
= 0
therefore the body comes to rest after 7 seconds.
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