Question

8. Tor F: During the "down" phase of a pushup (lowering your body towards the ground while bending your elbows), your triceps undergo an eccentric contraction. ben 9. Tor F: If the net force acting on an object is zero, the net torque on the object must also be zero. 10. Tor F: During a biceps curl exercise with a dumbbell, the moment arm of the biceps changes throughout the movement. 11. Tor F: In order for an object to be in static equilibrium, the net external force and the net external torque on the object must both be zero.

Answer 1

1. Eccentric contractions occur when the muscle lengthens under tension (usually when returning to its normal resting length). So it' false.

2. For an object to be in equilibrium, it must be experiencing no acceleration. This means that both the net force and the net torque on the object must be zero. IT's True.

3. A moment arm is simply the length between a joint axis and the line of force acting on that joint. so with each moment it changes. It's true.

4. Static equilibrium is the state in which a system is stable and at rest. To achieve complete static equilibrium, a system must have both rotational equilibrium (have a net torque of zero) and translational equilibrium (have a net force of zero). translational equilibrium: A state in which net force is equal to zero. It's true.