Answer:
1. Energy = 2880 Joules.
2. Energy = 60 Joules.
3. Quantity of charge = 120 Coulombs.
Explanation:
Given the following data;
1. Voltage = 12 Volts
Current = 0.5 Amps
Time, t = 8 mins to seconds = 8 * 60 = 480 seconds
To find the energy;
Power = current * voltage
Power = 12 * 0.5
Power = 6 Watts
Next, we find the energy transferred;
Energy = power * time
Energy = 6 * 480
Energy = 2880 Joules
2. Charge, Q = 4 coulombs
Potential difference, p.d = 15V
To find the total energy transferred;
Energy = Q * p.d
Energy = 4 * 15
Energy = 60 Joules
3. Voltage = 6 Volts
Current = 1 Amps
Time = 2 minutes to seconds = 2 * 60 = 120 seconds
To find the quantity of charge;
Quantity of charge = current * time
Quantity of charge = 1 * 120
Quantity of charge = 120 Coulombs
Answer:
52.47706 mph
54.5 mph
Explanation:
The average speed is given by


Julie's average speed on the way to Grandmother's house is 52.47706 mph

Average speed on the return trip is 54.5 mph
Answer:
Her computer is producing thermal energy, not heat.
Explanation:
Part a)
Power rated on the elevator is given as

now the mass that is lifted above is given as

height of the elevator lifted is

now the potential energy is given as


now power is defined as rate of energy



so it will take 13.5 s to lift up
Part b)
Electrical energy used




so electrical energy used in this process will be 120050 J