Answer:
A-Light from the Sun reflects off the Moon as it orbits Earth
<u>Answer</u>: The potential difference across the resistor is 12 volts.
<u>Explanation:</u>
To calculate the potential difference cross the resistor, we use Ohm's Law. This law states that the potential difference across two wires is directly proportional to the current flowing through that wire.
Mathematically,

Where,
V = potential difference = ?V
I = Current flowing = 1.2 A
R = Resistor = 
Putting values in above equation, we get:

Hence, the potential difference across the resistor is 12 volts
Internal energy of the system changes by ΔE = 178 J.
Heat given to the system = Q = +658 J.
According to the first law of thermodynamics,
ΔE = Q + W
178 = 658 + W
∴ W = 178-658 = -480 J
Minus sign indicates that work is done by the system.
The radius, r, of the child from the center of the wheel is
r = 1.3 m
The wheel makes one revolution in 4.2 s. Its angular velocity is
ω = (2π rad)/(4.2 s) = 1.496 rad/s
The linear speed of the child is the tangential velocity, given by
v = rω
= (1.3 m)*(1.496 rad/s)
= 1.945 m/s
Answer: 1.95 m/s (nearest hundredth)