Question

30 Physics 2210 Exam 3 -Conservation 19 2 points) A box slides down a ramp and comes to rest exactly at the bottom. Which of ng is true? The initial potential energy equals the final kinetic emergy . (b) The work done by friction equals the initial potential energy (c) Energy is not conserved in this situation. (d) The work done by friction is equal to zero. 2. [2 points) What is the main difference betwen elastic and inelastic collisions? .(a) Kinetic energy is not conserved in inelastic collisions (b) Kinetic energy is not conserved in elastic collisions. . (c) Momentum is not conserved in inelastic collisions. (d) Momentum is not conserved in elastic collisions 2 points] In pairs figure skating, a couple pushes each other and each of them slides in osite directions. Assume that the male skater is heavier than the female skater. Which of e following is true? . (a) Both skaters have equal momentum and equal kinetic energy . (b) Both skaters have equal kinetic energy, bat unequal momentum. c) Both skaters have equal momentum, but unequal kinetic energy d)The skaters have unequal momentum and unequal kinetic energy 2 points) As the earth spins about its axis causing day and night, what direction is its momentum vector? Draw a picture if it will help. (a) Angular moment um has no direction . (b) Tangential to the equator. (c) Outward from the earth at the equator. Old) Outward from the earth at the north pole.
please explain tbe correct answers

Answer 1

b) W. E. theorem integral F dx = delta KE mg dx + (F dx) = 0 mg dx = F dx rightarrow work same a) as some energy is lost in deformation for Inelastic collision c) From Momentum conservation, equal Momentum, but different velocitis From Right hand rule w^rightarrow upwards, so I w^rightarrow also upwards