A body of mass 2.5 kg takes 5 seconds to stop when a force 10 N is applied in a direction opposite
to the motion of the body. The initial speed of the body was:
(A) 20 m/s
(B) 10 m/s
(C) 15 m/s
(D) 25 m/s
Answers
Answered by
10
Answer:-
Given:-
- Mass of the body (m) = 2.5 kg
- Time taken to stop (t) = 5 s
- Force applied on it (F) = - 10 N (Force acted on the opposite side)
- Final velocity (v) = 0 m/s
To Find:-
Initial velocity (u) in the case.
___________...
We know,
F = ma
➽ F = m[(v - u)/t]
➽ F = m(-u/t)
(Since, v = 0)
where,
- F = Force,
- m = Mass,
- a = Acceleration,
- v = Final velocity &
- u = Initial velocity.
Let the initial velocity in this case be = u
∴ (2.5 kg) (- u/5s) = - 10 N
➵ 25/10 kg × -u/5s = - 10 kg m/s²
➵ (-25 u)/(50) kg s^-1 = - 10 kg m/s²
➵ - ½ u kg s^-1 = - 10 kg m/s²
➵ ½ u kg/s = 10 kg m/s²
➵ ½ u = (10 kg m/s²)/(kg) × s
➵ ½ u = 10 m/s
➵ u = 10 × 2 m/s
➵ u = 20 m/s
∴ ☑ (A) 20 m/s
Answered by
2
Answer:
answer is 10 m/s.....
you can trust me
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