Physics 101 Zacharias Exercise 11 Fall 2017 Name: Solmaz Rajahi Ahways pick the
ID: 1792474 • Letter: P
Question
Physics 101 Zacharias Exercise 11 Fall 2017 Name: Solmaz Rajahi Ahways pick the best answer 1.) Consider a mass of 4.0 kg moving horizontally in a straight line with a speed of 15.0 m's. Determine the kinetic energy of this mass. a.) 450 Joules b.) 295 Joules c.) 155 Joules d.) 600 Joules Answer: A 2.) One cubic meter of water has a mass of looo kilograms. The water falls (vert going over the edge. Cakculate the work done on this water as it falls a.) 632,800 Joules b.) 136.200 Joules c) 124,700 Joales d.) 499,800 Joules Answer increase of 3.) Determine the change in the kinetic energy of a 2.90 kilogram mass that experieneces an velocity from 3.20 m's to 5.70 m's. a.) 28.42 Joule b.) 41.82 Joule c) 32.26 Joule d.) 53.71 Joule Answer 4.) A 10.0 kilogram physics texthook accidentally falls out a 15 meter high window (initial velocity is zero). How much work is done by the force of gravity during the fall to the ground? a.) 4250 Joules b.) 1470 Joules c.) 3750 Joules d.) 2900 Joules Answer 5.) A mass drops (initially at rest) vertically a distance of 2.48 meter. Determine the speed (units - meter/second) of this mass after it falls the distance of 2.48 meter. a.) 6.02 m/'s b.) 6.97 m/s c.) 3.14 m's d.) 0.54 m's AnswerExplanation / Answer
1. K.E = 0.5mv2 = 0.5*4*(15)2 = 450 J
2. Work done will be lose in potential energy = mgh = 1000*9.8*51 = 499800 J
3. change in K.E = 0.5*2.90*((5.7)2-(3.2)2) = 32.26 J
4. Work done will be equal to gain in kinetic enery or loss in potential energy = mgh = 10*9.8*15 = 1470 J
5. change in kinetic energy will be equal to change in potential energy
0.5mv2 = mgh
v = (gh/0.5)1/2 = (9.8*2.48/0.5)1/2 = 6.97 m/s