Answer:
At 81. 52 Deg C its resistance will be 0.31 Ω.
Explanation:
The resistance of wire =
Where
=Resistance of wire at Temperature T
= Resistivity at temperature T ![=\rho_0 \ [1 \ + \alpha\ (T-T_0\ )]](https://tex.z-dn.net/?f=%3D%5Crho_0%20%5C%20%5B1%20%5C%20%2B%20%5Calpha%5C%20%28T-T_0%5C%20%29%5D)
Where 
l=Length of the wire
& A = Area of cross section of wire
For long and thin wire the resistance & resistivity relation will be as follows

![\frac{0.25}{0.31}=\frac{1}{[1+\alpha(T-20)]}](https://tex.z-dn.net/?f=%5Cfrac%7B0.25%7D%7B0.31%7D%3D%5Cfrac%7B1%7D%7B%5B1%2B%5Calpha%28T-20%29%5D%7D)



T = 81.52 Deg C
A pendulum is an object hung from a fixed point that swings back and forth under the action of gravity. In the example of the playground swing, the swing is supported by chains that are attached to fixed points at the top of the swing set. When the swing is raised and released, it will move freely back and forth due to the force of gravity on it. The swing continues moving back and forth without any extra outside help until friction (between the air and the swing and between the chains and the attachment points) slows it down and eventually stops it.
D=m÷v
so density would be 57.9 ÷ 3 = 19.3 g/cm³
Igneous intrusions form when magma cools and solidifies before it can reach the surface. An extrusion consists of extrusive rock; which forms above the surface of the crust.
Answer:
The force needed will be greater to hold the object at rest.
Explanation:
For a better understanding let's take a look at the attached image.
In the image there is an example of this condition, we have an object of 3 kg-f mass, the first angle between the horizontal and the inclined plane is 35°. When we increase the angle to 45°. We can realize that we need to hold the object with a stronger force.
The calculation and the equations based on Newton's laws can be found in the attached image.