a block of mass m rests on a block of mass m1 which is on a tabletop. a light string passes over a frictionless pulley and connects the blocks. the coefficient of kinetic friction between the blocks and between the block of mass m1 and the tabletop is the same. a force f pulls the upper block to the left and the lower block to the right. the blocks are moving at a constant speed.

Friction removes energy from objects in motion. which statement best describes how this works? a) friction transforms ke into thermal energy b) friction transfers thermal energy to ke c) friction transforms te into pe d) friction transforms pe into ke e) friction transfers ke into pe

The base of a 50-meter tower is at the origin; the base of a 50-meter tree is at (0, 50, 0). the ground is flat and the z-axis points upward. the following parametric equations describe the motion of six projectiles each launched at time t = 0 in seconds. (i) r (t) = (50 + t2)k (ii) r (t) = 2t2 j + 2t2k (iii) r (t) = 50 i + 50 j + (50 − t2)k (iv) r (t) = 2t j + (50 − t2)k (v) r (t) = (50 − 2t) i + 2t j + (50 − t)k (vi) r (t) = t i + t j + tk (a) which projectile is launched from the top of the tower and goes downward? at time t = , the projectile hits the ground at point (x, y, z) = . (b) which projectile hits the top of the tree?

"if the pressure acting on an ideal gas at constant temperature is tripled, its volume isa) reduced to one-third. b) increased by a factor of three. c) increased by a factor of two. d) reduced to one-half"