Answer:
1. a 
b 
c 
2. 
Explanation:
a). The work done by the tension is:




b). The work done potential of gravity




c). The work done by the normal force



2. The increase in thermal energy is:





Answer:
Given
Frequency (f) = 3Hz
Wavelength = 9 m
Speed = ?
Explanation:
we know
Speed = wavelength * frequency
= 9*3
= 27 m/ s
The current intensity is defined as the amount of charge flowing through a certain point of a wire divided by the time interval:

where Q is the charge and

is the time. Re-arranging the formula, we have

for the compressor in our problem, the intensity of current is I=66.1 A, while the time is

, so the amount of charge that crosses a certain point of the circuit during this time is
I think the answer would be physics.