Answer:
The extension of the wire is 0.362 mm.
Explanation:
Given;
mass of the object, m = 4.0 kg
length of the aluminum wire, L = 2.0 m
diameter of the wire, d = 2.0 mm
radius of the wire, r = d/2 = 1.0 mm = 0.001 m
The area of the wire is given by;
A = πr²
A = π(0.001)² = 3.142 x 10⁻⁶ m²
The downward force of the object on the wire is given by;
F = mg
F = 4 x 9.8 = 39.2 N
The Young's modulus of aluminum is given by;

Where;
Young's modulus of elasticity of aluminum = 69 x 10⁹ N/m²

Therefore, the extension of the wire is 0.362 mm.
about 5 watts (5W) of power
Answer:
3300J
Explanation:
Work done is the energy that is lost by the skater
Formula for workdone = 1/2*mV^2
m = 66kg
V = 10m/s
Work done = 1/2 * 66 * 10^2
= 3300J
Here in the process we require
1. Heat to melt down all ice
2. Heat to raise the temperature of whole water to 100 degree C
3. Heat to boil off the water
now here for the first part
Heat required to melt the ice


now heat required to raise the temperature to 100 degree C



Now heat required to boil it off


now the total heat required will be



so it required 287200 calorie heat to boil it all water