The first thing you should know is that the work is defined as:
W = F * d
Where
F = force
d = displacement
We have then
(a) the block
F = (0.2) * (100) = 20
d = 100
W = (20) * (100) = 2000 ft.lbf
(b) the man as the system.
F = (0.2) * (100 + 180) = 56
d = 100
W = (56) * (100) = 5600 ft.lbf
answer:
(a) 2000 ft.lbf
(b) 5600 ft.lbf
In general,
Power = (energy moved) / (time to move the energy) .
If it's mechanical power, then
Power = (work done) / (time to do the work) .
If it's electrical power, then it can be any one of these:
Power = (volts) x (amperes)
Power = (volts)² / (resistance, ohms)
Power = (amperes)² x (resistance, ohms) .
Whatever kind of energy you're dealing with, power always
turns out to be
(amount of energy produced, used, or moved)
divided by
(time taken to produce, use, or move the energy) .
Complete Question
The complete question is shown on the first uploaded image
Answer:
Explanation:
From he question we are told that
The first mass is 
The second mass is 
From the question we can see that at equilibrium the moment about the point where the string holding the bar (where 
are hanged ) is attached is zero
Therefore we can say that
Making x the subject of the formula
Looking at the diagram we can see that the tension T on the string holding the bar where 
are hanged is as a result of the masses (
)
Also at equilibrium the moment about the point where the string holding the bar (where (
) and 
are hanged ) is attached is zero
So basically
Making subject
Answer:
When elements bond together or when bonds of compounds are broken and form a new substance
Explanation:
Turn off lights when leaving rooms.
Unplug unused appliances. Even when powered off these appliances use electricity.
Replace regular light bulbs with energy saving bulbs.
