To solve this problem, we must take two important steps. First we will convert all the given units, to international system. Later we will define the torque, which is given as the product between the radius of application of the force and the Force acting on the body. Mathematically the latter is,

Here,
r = Radius
F = Force
Now the units,

Replacing,


Therefore the torque that the muscle produces on the wrist is 
Answer:
The kinetic energy is 86.6 zepto joules.
Explanation:
Given that,
Number of orbit n =5
We know that,
Bohr's radius for hydrogen atom is

Now, put the value of n in the formula of radius


We need to calculate the kinetic energy
Using formula of kinetic energy

Put the value into the formula


We know that,

The kinetic energy is


Hence, The kinetic energy is 86.6 zepto joules.
The answer is C.
Ionic compounds are those that bring together anions and cations bonded together by ionic bonds. The electrostatic forces of the different charges are significant in the bonds that make them strong hence require high energy to break them (high melting point). Due to the regular structure of ionic compound that tend to form lattices in solid form, when struck, they shatter along the lines of weakness of the lattice.
Convert 220 lb to kg.
220/2.2 = 100kg.
W = Fd (In this case, F is the weight)
W = (100)(2)
W = 200J
P = W/t
P = (200)/(1.2)
P = 166.67W