Answer:
37.5 N Hard
Explanation:
Hook's law: The force applied to an elastic material is directly proportional to the extension provided the elastic limit of the material is not exceeded.
Using the expression for hook's law,
F = ke.............. Equation 1
F = Force of the athlete, k = force constant of the spring, e = extension/compression of the spring.
Given: k = 750 N/m, e = 5.0 cm = 0.05 m
Substitute into equation 1
F = 750(0.05)
F = 37.5 N
Hence the athlete is pushing 37.5 N hard
Answer:
Option C. 16.6 m/s
Explanation:
To round this 16.558 m/s to 3sf, we need to count the number beginning from 1. When we get to the 3rd number( ie 5), we'll examine the fourth number(i.e 5)to see if it less than five or greater. If it less than five, then we'll discard it. But if it five or greater, we'll approximate it and add it to the 3rd number.
So.
16.558 m/s = 16.6m/s to 3sf
Answer:........u are so sweet
Answer:
Explanation:
Given:
- thickness of the base of the kettle,
- radius of the base of the kettle,
- temperature of the top surface of the kettle base,
- rate of heat transfer through the kettle to boil water,
- We have the latent heat vaporization of water,
- and thermal conductivity of aluminium,
<u>So, the heat rate:</u>
<u>From the Fourier's law of conduction we have:</u>
where:
area of the surface through which conduction occurs
temperature of the bottom surface
is the temperature of the bottom of the base surface of the kettle.
