Answer:
6
Explanation
Any numbers in scientific notation are considered significant. For example, 4.300 x 10-4 has 4 significant figures.
Answer From Gauth Math
Answer:
Explanation:
The thermal efficiency of a Power cycle 
where;




--- (1)
---- (2)
The coefficient of performance is:

let replace the value of
in the above equation then;



The
On the other hand, the heat pump

By replacing equation (1) into the above equation; we have:



t
D all of the above
Hope it helps
The question isn't clear enough, I think it ask us to calculate the linear speed of a point at the edge of the DVD.
Now let's imagine we're a point at the edge of the DVD, we're undergoing a circular motion. Each minute we will complete a circular track 7200 times, now we need to know the distance we travel each turn. The perimeter of the DVD, a circular object is:

Know recall that:

We now need to know how much distance is traveled during a minute or 60 seconds:

Finally we divide this result with t=60 seconds:


Where the distance units were named units as the length unit is not specified in this exercise.<span />
Answer:
Explanation:
The change in force = 9.81(1.95 - 0.300) = 16.2 N
The change in length is 0.750 - 0.200 = 0.550 m
K = ΔF/Δx = 16.2/0.550 = 29.4 N/m