7 V 0.5kg
in Practice
1. A mass spring system is in SHM in the horizontal direction. If the mass is 0.25
kg, spring constant is 12N/m, and the amplitude is 15 cm,
a) what is the maximum speed of the mass?
Ans: 1.01 M/S
b) What is the speed at a half-amplitude position? Ans: 0.12 M/S
2. The mass m is now stretched a distance of 8 cm and held. What is the potential ener-
gy? (k = 196 N/m)
Ans: 0.6272)

Unpolarized light falls on two polarizer sheets whose transmission axes are at right angles. a third polarizer is placed between the first two so that its axis makes a 52-degree angle with the axis of the first polarizer. a) what fraction of the incident light intensity is transmitted through the first polaroid? b) what fraction of the incident light intensity is transmitted through the second polaroid? c) what is the angle of polarization of the light that enters the third polaroid? d) what fraction of the incident light intensity is transmitted through the third polaroid. e) what happens if the middle polaroid is removed?

Arigid tank is divided into two equal parts by a partition. one part of the tank contains 3 kg of compressed liquid water at 400 kpa and 60°c while the other part is evacuated. the partition is now removed, and the water expands to fill the entire tank. determine the entropy change of water during this process, if the final pressure in the tank is 40 kpa. use steam tables.

How does a circuit breaker protect a refrigerator? a. when the current is too high, a metal strip in the fuse melts and opens the circuit. b. when the resistance is too high , a re-settable which opens a circuit c. when the current is too high , a re-settable switch opens the circuit d. when the resistance is too high a metal strip in the fuse melts and opens the circuit