the length of a metal rod at 0 degree is 225cm. on heating to 300 degree, its length increases to 225.3 cm. calculate the coefficient of linear expansion of the metal rod

Four objects are being tested to see how they are affected by fluid friction. object w has a surface area of 4.5 cm2, object x has a surface area of 2.5 cm2, object y has a surface area of 6.2 cm2, and object z has a surface area of 3 cm2. which object would experience the most fluid friction?

A23 kg log of wood begins from rest, 300 m up a sluice (a water track used to transport logs, think of it as an inclined plane with negligible friction) inclined at 20° to the horizontal. after it reaches the flat waterway at the bottom it collides elastically with a 100 kg block of wood initially at rest near the base of the incline. (a) how long does it take the 23 kg log to travel down the incline? (b) what is the speed of the 23 kg log at the bottom of the incline? (c) what are the velocities of both blocks of wood after the collision? (d) what is the total kinetic energy before the collision? (e) what is the kinetic energy of the 23 kg log after the collision? (f) what is the kinetic energy of the 100 kg block of wood after the collision? (g) what is the total kinetic energy after the collision? (h) compare the total initial and total final kinetic energies. is this consistent with what you would expect for elastic collisions? explain!

Which changes would result in a decrease in the gravitational force btween two objects? check all that apply