Question

*Part 1 Your answer is correct. (1) Two external forces act on a system, <14, -17, 38> N and <20, -11, -28> N. What is the net force acting on the system? > N Answer * 1: the tolerance is +/-2% Answer * 2: the tolerance is +/-2% Answer 3: the tolerance is +/-2% *Part 2 Your answer is partially correct. Try again (2) A hockey puck initially has momentum <0, 0, 13> kg-m/s. It slides along the ice, gradually slowing down, until it comes to a stop (a) What was the impulse applied by the ice to the hockey puck? 769 (vector) impulse is< > N-S Answer *1: the tolerance is +/-2% Answer 2: the tolerance is +/-2% Answer *3: the tolerance is +/-2% *Part 3 Your answer is incorrect. Try again (b) It took 2 seconds for the puck to come to a stop. During this time interval, what was the net force on the puck by the ice and the air (assuming this force was constant)? 17 14 Answer *1: the tolerance is +/-2% Answer * 2: the tolerance is +/-2% Answer * 3: the tolerance is +/-2%

Answer 1

We have to find impulse which is change in momentum, also force is equal to rate of change of momentum, we use these concepts in this solution ,

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We have to find impulse which is change in momentum, also force is equal to rate of change of momentum, we use these concepts in this solution, part - 2) impulse = delta p = p_f - p_i = 0 - (13 kg middot m/s k^^) = -13kg m/s k^^= < 0, 0, -13 > N middot s part - 3) F = delta p/delta t = -13 kg middot m/s k^^/25 = -6.5 N k^^= < 0, 0, -6.5 > N