Exam 9: Work and Kinetic Energy

In the figure,a constant external force P = 160 N is applied to a 20.0-kg box,which is on a rough horizontal surface.While the force pushes the box a distance of 8.00 m,the speed changes from 0.500 m/s to 2.60 m/s.The work done by friction during this process is closest to

A 1500-kg car accelerates from 0 to 25 m/s in 7.0 s with negligible friction and air resistance.What is the average power delivered by the engine? (1 hp = 746 W)

A rectangular box is positioned with its vertices at the following points: A = (0,0,0)C = (2,4,0)E = (0,0,3)G = (2,4,3) B = (2,0,0)D = (0,4,0)F = (2,0,3)H = (0,4,3) If the coordinates all have three significant figures,the angle between the line segments AG and AH is closest to:

What is the angle between the vector = +3 - 2 - 3 and the +y-axis?

If a force always acts perpendicular to an object's direction of motion,that force cannot change the object's kinetic energy.

Determine the scalar product of = 6.0 + 4.0 - 2.0 and = 5.0 - 6.0 - 3.0 .