Most of the motion generated by joints in the human body are examples of levers. an example of a third class lever is the forearm; the force which generates the motion is located in‑between the pivot point and the resistance force. the elbow acts as the pivot point, the biceps muscle pulls up on the forearm to move the mass which is held in the hand. imagine someone is holding an object in her hand with her forearm horizontal and her upper arm vertical so her elbow creates a 90∘ angle. if her biceps attach to her forearm 0.0597 m from the elbow and make an angle of 29.0∘ with the vertical while a 2.00 kg mass is held in her hand 29.03 cm from the elbow, what force is exerted by the biceps muscle? ignore the mass of the forearm.

force due to Biceps is 109.1 N

Explanation:

As we know that the system of mass with the arm is at rest

So here net force and torque must be zero about the elbow must be zero

So we will have

Torque due to force of Biceps = Torque due to weight held

now by force balance

So force due to Biceps is 109.1 N

okay i have so many questions. but the big one here is: um wt..f is this mess? ?

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.