A compound machine is a combination of at least two simple machines. Simple machines can be a lever, a wedge, a while + axle, an incline plane, a pulley, and a screw.
There are many examples of compound machines. One of them is a showel that combines a wedge (the scoop part of shovel) and a lever (the handle to transfer the force to lift).
A much more complex compound machine is a bicycle, comprising simple machines ranging from wheels and axles, to screws, and levers (think of the pedals).
Answer:
605 J
Explanation:
Efficiency = work out / work in
0.78 = W / 775 J
W = 605 J
W = Fd = 4(2100) = 8400 J
So the answer is A) 8400 J
I was just rewriting my notes on the work lesson I did in class today, so I saw this question at the perfect time!! :)
Hope it helps!! :)
As stated, the impulse and momentum definitions will be used to later find the value of time through the force of gravity. According to the theory, the impulse formula is given as,
Here,
F = Force
Change in time
Now using the impulse theorem we have that,
Change in Impulse = Change in momentum
(1)
The change in momentum is given as
The force due to gravity is through the Newton's second law
Here,
m = mass
g = Acceleration due to gravity
Substitute the value in (1)
Therefore it will take 0.51s.
