Lets do the sum of the forces about the elbow joint.
Fm = Force of Muscle; Fe = Force Elbow; Fb = Force Ball
Sum Force about Joint = (-2.5)Fm + 12.5Fe + 30Fb = 0
(-2.5)Fm + 12.5(2.8) + 30(6.9) = 0
Fm = 96.8kg
Fm = 96.8 * 9.8 = 948.6N
Do you understand why the -2.5 is negative?
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Because I put the origin at the joint. So when you go left it is negative and when you go right it is positive. </span>
The maximum speed is 0.55 m/s
Explanation:
For an object in uniform circular motion, the force of friction between the object and the ground provides the centripetal force required to keep the body in motion. Therefore we can write:

where the term on the left is the frictional force and the term on the right is the centripetal force, and where
is the coefficient of static friction
m is the mass of the body
g is the gravitational acceleration
v is the speed of the body
r is the radius of the circular path
In this problem, we have:

r = 0.102 m

Substituting and re-arranging, we find the maximum speed v at which the salt shaker can rotate:

Learn more about circular motion:
brainly.com/question/2562955
brainly.com/question/6372960
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<span>Let's put it this way. Say you have a killer-whale and a penguin. Killer-whales are major predators to penguins. Now, say the killer-whale population increases. The penguins would be eaten more by the killer-whales, then causing a population decrease for the penguins. If the population decreases, they're won't be enough penguins, and they most likely will become extinct, as well as causing a population decrease for the killer-whales as well. Whereas, vis versa, they're were a killer-whale population decrease. The penguins would be less hunted, therefore, creating a population increase for the penguins.</span>
Meters ?? or just a variable
Answer:
D. A Molecule
Explanation:
<em>The smallest particle of a compound that still has the properties of the compound is a molecule. It is composed of two or more bonded atoms.</em>