The pH scale is used to tell if a substance is an acid or base. Substances with a pH
of 7 are neutral. An acid is anything
below 7 and a base is anything above
7.What would a household cleaner with a
pH of 10 be considered on the pH scale?
A. base
B. acid
C. neutral

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!

Velocity is a description of both speed and direction, therefore it - a vector - a force arrow - the same as acceleration - a magnitude

What is the speed of an object at a given moment?