Firefighter Joe noticed a cat stuck high in a tree. He needs to know exactly how high the cat is in order to get the proper ladder for the job. Joe has a mirror and he understands that when light reflects, the angle of incidence equals the angle of reflection. Joe sets the mirror on the ground and backs up until he can see the reflection of the cat in the mirror. When Joe is lined up correctly, his eyes are 5.5 feet above the ground, his is standing 3 feet from the mirror, and the mirror is 12 feet from the tree. How high is the cat off of the ground

Spend time observing or thinking about events that involve matter and energy. which events can you explain? which events can’t you explain?

1. consider the case in which air fills air shocks on a truck trailer. the pressure in the shocks is 2 mpa. the temperature is 300 k. the diameter of the shock piston is 10 cm and the initial length of the cylindrical cavity containing the compressed air is 40 cm. a. the truck is gradually loaded over a period of a day in a static setting. the temperature is held constant for the atmosphere and thus for the gas shock. calculate the compressibility of the air in the shock for this condition when the truck is initially being loaded. b. if the shocks were loaded in a dynamic setting by driving over bumps, what would be the compressibility? state your assumption. c. what is the initial load on the shock if the shock is in an atmospheric 100 kpa? d. if the shock is compressed using the process described in part a, and the air shock compressed air cavity length decreases to 20 cm, what is the additional load applied to the shock?

What do you think car designers do if the damage caused by a crash test is too severe?