##### A cook holds a 2.59-kg carton of milk at arm's length (see the figure below). What force vector F B

label Physics
account_circle Unassigned
schedule 1 Day
account_balance_wallet \$5

A cook holds a 2.59-kg carton of milk at arm's length (see the figure below). What force vector F B must be exerted by the biceps muscle? (Ignore the weight of the forearm. State the magnitude of the force vector F B.) N

Jun 11th, 2015

Thank you for the opportunity to help you with your question!

post the picture too..............i don't want to answer the wrong thing

Please let me know if you need any clarification. I'm always happy to answer your questions.
Jun 11th, 2015

Jun 11th, 2015

The torques created by the weights are clockwise relative to the pivot, while the torque created by the biceps is counterclockwise; thus, the second condition for equilibrium (netτ=0) becomes

r2wa+r3wb=r1FB.

Note that sinθ=1 for all forces, since θ=90º for all forces. This equation can easily be solved for FB in terms of known quantities, yielding

FB=r2wa+r3wbr1.

Entering the known values gives

FB=(0.160m)(2.50kg)(9.80m/s2)+(0.380m)(4.00kg)(9.80m/s2)0.0400m

which yields

FB=470 N.

Now, the combined weight of the arm and its load is (6.50 kg)(9.80m/s2)=63.7 N, so that the ratio of the force exerted by the biceps to the total weight is

FBwa+wb=47063.7=7.38.

Jun 11th, 2015

...
Jun 11th, 2015
...
Jun 11th, 2015
Oct 18th, 2017
check_circle
Mark as Final Answer
check_circle
Unmark as Final Answer
check_circle