A 4 kg object at rest is subjected to a force (2i+6j)N. What is its velocity vector after after 2 sec
Answers
Answered by
36
GiveN :
- Mass (m) = 4 kg
- F = (2i + 6j) N
- Time = 2s
- Initial velocity (u) = 0 m/s
To FinD :
- Velocity Vector
SolutioN :
⇒F = dp/dt
⇒Δp = F.dt
Integrate both sides
⇒∫Δp = ∫F.dt
⇒p = (2i +6j) * 2
⇒p = mv = (2i + 6j) * 2
⇒v = ((2i + 6j) * 2)/4
⇒v = (2i + 6j)/2
⇒v = (i + 3j) m/s
BrainIyMSDhoni:
Great :)
Answered by
34
Answer:
- velocity vector of object = ( i + 3 j ) m/s
Explanation:
Given,
- Mass of object, m = 4 kg
- Force vector, F = ( 2i + 6j ) N
- Initial velocity of object, u = 0
- Time, t = 2 sec
To find,
- Velocity vector of object after time (t), v =?
Knowledge required,
- Newton's second law of motion
F = m a
- First equation of motion
v = u + a t
[ Where F is force, m is mass, a is acceleration, v is final velocity and t is time taken ]
Solution,
Using Newton's second law of motion
→ F = m a
→ a = F / m
→ a = ( 2 i + 6 j ) / ( 4 )
→ a = ( 0.5 i + 1.5 j ) m/s²
Now using first equation of motion
→ v = u + a t
→ v = ( 0 ) + ( 0.5 i + 1.5 j ) ( 2 )
→ v = (i + 3 j) m/s
Therefore,
- Velocity vector of object is ( i + 3 j ) m/s.
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