Bulacan State University
1. Calculate the quantity of heat energy which must be transferred to 2.25 kg of brass to
raise its temperature from 20 ℃ to 240 ℃ if the specific heat of brass is 394 J.kg-K.
2. Find the change in temperature produced by 10 kJ of heat energy added to 500 g
copper. Specific heat of copper 0.39 kJ/kg-K.
3. Explain why, for a gas, the specific heat at constant volume has a different value
from the specific heat at constant pressure.
An ideal gas is contained in a cylinder fitted with a piston. Initially the temperature of the
gas is 15℃. If the mass of the gas is 0.035 kg, calculate the quantity of heat energy
required to raise the temperature of the gas to 150 ℃ when:
(a) The piston is fixed;
(b) The piston moves and the pressure is constant.
For the gas, 𝑐𝑣 = 676 J/kg-K and 𝑐𝑝 = 925 J/kg-K.
Diana invested $3000 in a savings account for 3 years. She earned $450 in interest over that time period. What interest rate did she earn? Use the formula I=Prt to find your answer, where I is interest, P is principal, r is rate and t is time. Enter your solution in decimal form rounded to the nearest hundredth. For example, if your solution is 12%, you would enter 0.12.
A 2.75 kg particle moves as function of time as follows: x(t) = 5cos(1.25t+π/4); where
distance is measured in meter and time in seconds. (a) What is the amplitude, frequency,
angular frequency, and period of this motion? (b) What is the equation of the velocity of
this particle? (c) What is the equation of the acceleration of this particle? (d) What is the
spring constant? (e) What are the equations for the potential and kinetic energies of the
particle? (f) What is the total energy?