Question

What is the magnitude of the force exerted by the biceps FbicepsFbicepsF_biceps? What is the magnitude of the force exerted by the elbow FelbowFelbowF_elbow

Answer 1

The force of forearm is 239.9 N

The force of elbow is 215.89 N

Step-by-step explanation:

Suppose, When you lift an object by moving only your forearm, the main lifting muscle in your arm is the biceps. Suppose the mass of a forearm is 1.50 kg. If the biceps is connected to the forearm a distance
`d_(b)` 2.50 cm from the elbow, how much force
`F_(b)` must the biceps exert to hold a 950 g ball at the end of the forearm at distance dball J 36.0 cm from the elbow, with the forearm parallel to the floor? How much force
`F_(l)` must the elbow exert,

Given that,

Mass of forearm = 1.50 kg

Distance of forearm = 2.50 cm

Mass of ball = 950 g

Distance of ball = 36.0 cm

We need to calculate the force of forearm

Using balancing torque about elbow

`F_(b)* d_(b)=w_(f)*(d_(f))/(2)+w_(ball)* d_(ball)`

Put the value into the formula

`F_(b)* 0.025= 1.50*9.8*(0.36)/(2)+0.95*9.8*0.36`

`F_(b)=(1.50*9.8*(0.36)/(2)+0.95*9.8*0.36)/(0.025)`

`F_(b)=239.9\ N`

We need to calculate the force of elbow

Using balancing force

`F_(b)=F_(l)+w_(f)+w_(b)`

`F_(l)=F_(b)-w_(f)-w_(b)`

Put the value into the formula

`F_(l)=239.9-(1.50*9.8)-(0.95*9.8)`

`F_(l)=215.89\ N`

Hence, The force of forearm is 239.9 N

The force of elbow is 215.89 N