Answer:
84.4 %
Explanation:
Mechanical efficiency = output work/input work × 100 %
output work = 432 J of work for the bike to turn the gears
input work = 512 J of work to ride.
Mechanical efficiency = 432 J/512 J × 100 %
= 0.844 × 100%
= 84.4 %
Answer:
15.34 kVA
Explanation:
A motor is a device that converts electrical energy into mechanical energy. It takes in electrical energy at the input and produce torque (motion) at the output.
The power consumption for a three phase motor is the product of voltage and current and √3. The √3 is because it is a three phase supply.
Hence Power (P) =√3 × voltage (V) × current (I)
P = √3 × V × I
Given that voltage (V) = 460 V, current (I) = 17 A. Hence:
P = √3 × V × I = √3 × 460 × 17 = 13544.64 VA
But 1000 VA = 1 kVA. Hence:

Answer:
Current, I = 0.000109 Amps
Explanation:
Given the following data;
Voltage = 6V
Resistance = 55,000 Ohms
To find the current flowing through the circuit;
Ohm's law states that at constant temperature, the current flowing in an electrical circuit is directly proportional to the voltage applied across the two points and inversely proportional to the resistance in the electrical circuit.
Mathematically, Ohm's law is given by the formula;
Where;
V represents voltage measured in voltage.
I represents current measured in amperes.
R represents resistance measured in ohms.
Making current the subject of formula, we have;
Substituting into the formula, we have;
Current, I = 0.000109 Amps