A 1300 kg car moves along a horizontal road at speed v0 = 26.4 m/s. The road is wet, so the static friction coefficient between the tires and the road is only μs = 0.129 and the kinetic friction coefficient is even lower, μk = 0.0903. 2
What is the shortest possible stopping dis- tance for the car under such conditions? Use g = 9.81 m/s2 and neglect the reaction time of the driver.
1. 344 m
A loaded truck can accelerate at 4 m/s . It loses its load so that it is only 0.3 as massive.
The acceleration of gravity is 9.81 m/s .

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!

Imagine you are standing in the antarctic during the southern hemisphere summer. the sky is clear and blue. there are no clouds in the sky. your shadow is cast on the icy ground. what is the color of the shadow?

On a day when the barometer reads 75.23 cm, a reaction vessel holds 250 ml of ideal gas at 20 celsius. an oil manometer ( ρ= 810 kg/m^3) reads the pressure in the vessel to be 41 cm of oil and below atmospheric pressure. what volume will the gas occupy under s. t.p.?