Heating Processes
A 500g block of copper is heated from 25°C to 75°C. The specific heat capacity of copper is 385 J kg-1 °C-1
(a) Calculate the amount of heat energy required to raise the temperature of the copper block.
9625 J
A laptop charger provides a constant current of 2.50 A for 3.00 hours. Calculate the total charge transferred to the laptop in this time.
2.70 x 104 C
A particular isotope of uranium-238 undergoes alpha decay. Write the nuclear equation for this decay and identify the products.
Th-90+a42+energy
A car accelerates from rest to a speed of 20 m/s in 10 seconds.
(a) 2 m/s².
(b) 300m
A sound wave travels through the air at 343 m/s. If its frequency is 256 Hz, calculate the wavelength of the sound wave.
1.34m
A 1.2 kg block of aluminum is placed in a hot water bath at 100°C. After reaching thermal equilibrium, it is removed and placed in 0.5 kg of water at 15°C. The specific heat capacity of aluminum is 900 J kg-1 °C-1 and for water is 4186 J kg-1 °C-1 . Calculate the final temperature of the system.
43.9°C
A portable charger delivers a current of 2.50 A at 18.0 V for 3.00 hours. Calculate:
(a) The total charge delivered by the charger.
(b) The total energy transferred to the laptop during this time.
(b) 4.86 x 105 J
A sample of radioactive iodine-131 has a half-life of 8 days. If you start with 80 grams, how much will remain after 8 days?
40.0g
A cyclist rides 120 km east and then turns north to ride another 40 km.
(a) 126 km
(b) N 71.6o E
A person walks between two speakers that are producing sound waves of the same frequency in phase. The person notices that at some points the sound is louder, and at other points it is quieter.
(a) What is the phenomenon being described?
(b) Explain why the person experiences this phenomenon as they walk.
(a) Interference
(b) As the person walks, the sound waves from the two speakers arrive with different path differences, causing constructive interference (louder sound) at some points and destructive interference (quieter sound) at others.
A 250g piece of iron is heated to 200°C and then dropped into 0.75 kg of water at 25°C in an insulated container. The specific heat capacity of iron is 450 J kg-1 °C-1 and water is 4186 J kg-1 °C-1 .
Calculate the final equilibrium temperature of the system.
31.1°C
A complex circuit consists of three resistors: R1=10.0Ω, R2=6.00Ω and R3=3.00 Ω, connected in series. The circuit is powered by a 24.0 V battery.
(a) Calculate the total resistance of the circuit.
(b) Determine the total current flowing through the circuit.
(c) Calculate the voltage drop across the 6.00Ω
(a) 19.0Ω
(b) 1.26A
(c) 7.56V
In a nuclear reaction, 1.0 kg of uranium-235 undergoes fission, releasing 200 MeV per fission event. Calculate the total energy released in joules, given that there are approximately 2.56 x 1024 uranium-235 nuclei in 1 kg.
8.20×1013J
A ball is thrown vertically upwards with a speed of 15 m/s from a height of 2.0 m.
(a) 13.5 m
(b) 3.19s
A tuning fork vibrates at 440 Hz. The sound wave it produces travels at 343 m/s in air.
(a) Calculate the wavelength of the sound produced by the tuning fork.
(b) The sound wave encounters a wall with a small opening. Sketch the diffraction pattern you would expect if the wavelength of the sound is larger than the opening size.
(a) 0.780 m
(b) Wavelength the same, curved after aperture
0.3 kg sample of water at 90°C is cooled by adding 0.2 kg of ice at -5°C.
(a) Calculate the final temperature of the water-ice mixture.
(b) Determine the mass of ice that melts completely in the process.
(a) 21.0°C.
(b) 0.200 kg
In a different circuit, two resistors, R1=4.0Ω and R2=12.0Ω, are connected in parallel. This parallel arrangement is then connected in series to a 16.0Ω resistor and a 24.0 V battery.
(a) Calculate the total resistance of the circuit.
(b) Determine the total current supplied by the battery
(a) 19.0Ω
(b) 1.26A
Given the masses of the constituents of a lithium-6 nucleus (3 protons and 3 neutrons), calculate the binding energy of lithium-6.
30.5 MeV
An object is dropped from a height of 45 m. Calculate the time it takes for the object to reach the ground (ignore air resistance).
3.03 s
Two loudspeakers are positioned 5 meters apart, both emitting a sound with a frequency of 500 Hz. A listener stands 10 meters directly in front of one speaker. The speed of sound is 343 m/s.
a. Calculate the wavelength of the sound wave.
(a) 0.686 m
A solar water heater uses sunlight to heat 50 liters of water. The water starts at 20°C and needs to be heated to 60°C.
(a) Calculate the amount of energy required to heat the water.
(b) If the solar panels have an efficiency of 60% and receive sunlight at a rate of 800 W/m² over an area of 3 m², calculate the time (in hours) required to heat the water.
(a) 8.36 x 106 J
(b) 1.61 hrs
A circuit contains two resistors R1=3.00Ω and R2=6.00Ω, connected in parallel, and a third resistor R3=12.0Ω connected in series with the parallel combination. The circuit is connected to a 30.0 V battery.
Calculate:
(a) The total resistance of the circuit.
(b) The current flowing through the 12.0Ω resistor.
(c) The power dissipated by the 3.00Ω resistor.
(a) 14.0Ω
(b) 2.14A
(c) 6.12 W
In the fission of uranium-235 induced by a neutron, the reaction produces barium-141, krypton-92, and three neutrons. Calculate the energy released given the following masses:
173 MeV
A 10 kg box is pushed across a surface with a constant force of 50 N at an angle of 30° to the horizontal.
(a) 123 N
(b) 1.87 m/s²
A speaker is placed at the end of a closed-end tube that is 0.85 m long. The speed of sound is 346 m/s.
(a) Draw and label the particle displacement envelope of the 3rd harmonic in the tube.
(b) Calculate the frequency of the 3rd harmonic.
(a)
(b) 306 Hz