I attached a Diagram for this problem.
We star considering the system is in equlibrium, so
Fm makes
with vertical
Fm makes 70 with vertical
Applying summatory in X we have,


We know that W is equal to

Substituting,




<em>For the second part we know that the reaction force Fj on deltoid Muscle is equal to Fm, We can assume also that</em> 
Answer:
If there is no damping, the amount of transmitted vibration that the microscope experienced is = 
Explanation:
The motion of the ceiling is y = Y sinωt
y = 0.05 sin (2 π × 2) t
y = 0.05 sin 4 π t
K = 25 lb/ft × 4 sorings
K = 100 lb/ft
Amplitude of the microscope ![\frac{X}{Y}= [\frac{1+2 \epsilon (\omega/ W_n)^2}{(1-(\frac{\omega}{W_n})^2)^2+(2 \epsilon \frac{\omega}{W_n})^2}]](https://tex.z-dn.net/?f=%5Cfrac%7BX%7D%7BY%7D%3D%20%5B%5Cfrac%7B1%2B2%20%5Cepsilon%20%28%5Comega%2F%20W_n%29%5E2%7D%7B%281-%28%5Cfrac%7B%5Comega%7D%7BW_n%7D%29%5E2%29%5E2%2B%282%20%5Cepsilon%20%20%5Cfrac%7B%5Comega%7D%7BW_n%7D%29%5E2%7D%5D)
where;


= 
= 4.0124
replacing them into the above equation and making X the subject of the formula:



Therefore; If there is no damping, the amount of transmitted vibration that the microscope experienced is = 
I think it's A) Sunspots. I hope this helps:)
If a man pushes on a wall with some force then according to Newton's third law, wall will also apply force on man with same magnitude but opposite in direction.
Answer:
a) 3.43 m/s
Explanation:
Due to the law of conservation of momentum, the total momentum of the bullet - rifle system must be conserved.
The total momentum before the bullet is shot is zero, because they are both at rest, so:

Instead the total momentum of the system after the shot is:

where:
m = 0.006 kg is the mass of the bullet
M = 1.4 kg is the mass of the rifle
v = 800 m/s is the velocity of the bullet
V is the recoil velocity of the rifle
The total momentum is conserved, therefore we can write:

Which means:

Solving for V, we can find the recoil velocity of the rifle:

where the negative sign indicates that the velocity is opposite to direction of the bullet: so the recoil speed is
a) 3.43 m/s