Answers

The Brainliest Answer!
2015-10-26T21:58:45+05:30
Assume right as i direction and upward as j direction
mass = 100g = 0.1kg

initial velocity =5(sin60 i + cos60 j) = 5(√3/2i + 1/2j) m/s
initial momentum = 0.1×5(√3/2i + 1/2j) kgm/s = 0.5(√3/2i + 1/2j) kgm/s

final velocity = 5(sin60 (-i) + cos60 j) = 5(-√3/2i + 1/2j) m/s
final momentum = 0.1×5(-√3/2i + 1/2j) kgm/s = 0.5(-√3/2i + 1/2j) kgm/s

change in momentum = 0.5(-√3/2i + 1/2j) - 0.5(√3/2i + 1/2j)
                                = -√3/4i + 1/4j -√3/4i - 1/4j
                                = -√3/4i -√3/4i =  -√3/2i kgm/s
time taken = 2×10⁻³ s

force = change in momentum/time
        = -√3/2 / 2×10⁻³ i N
        = -1000√3/4 i N
        = -250√3 i N
since force is negative, direction is opposite of i or direction is to the left.
Answer is C.
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