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CHECK YOURSELF ANSWERS
14.0 Ã 3.0 â (â4.0 Ã 8.0) = 44 N s.
2B, force is the rate of change of momentum
3She leaves the ground with a speed found from
v=2ghââââ=4.0Â m sâ1
So, the impulse is
J = mv â 0 = 40 Ã 4.0 = 160 N s
4Momentum is conserved but kinetic energy increases.
5The force is equal to the rate of change of momentum of the water, which is 20 Ã 15 = 300 N.
