4. Biomechanics

Kinetics Basics — Quiz

Test your understanding of kinetics basics with 5 practice questions.

Practice Questions

Question 1

A weightlifter is performing a deadlift. If the force exerted by the weightlifter on the barbell is $1500 \text{ N}$ and the barbell's mass is $100 \text{ kg}$, what is the net vertical force acting on the barbell during the initial lift, assuming the barbell is accelerating upwards at $5 \text{ m/s}^2$? (Assume $g = 9.81 \text{ m/s}^2$)

Question 2

During a squat exercise, a person's center of mass (COM) shifts. Which of the following statements accurately describes the optimal positioning of the COM relative to the base of support (BOS) for maintaining stability throughout the movement?

Question 3

A runner is accelerating during a sprint. If the horizontal ground reaction force (GRF) acting on the runner is $800 \text{ N}$ and the runner's mass is $70 \text{ kg}$, what is the runner's horizontal acceleration?

Question 4

Consider a scenario where a person is performing a single-arm dumbbell row. If the dumbbell's mass is $20 \text{ kg}$ and the perpendicular distance from the shoulder joint (axis of rotation) to the line of action of the gravitational force of the dumbbell is $0.3 \text{ m}$, what is the magnitude of the gravitational moment (torque) created by the dumbbell around the shoulder joint? (Assume $g = 9.81 \text{ m/s}^2$)

Question 5

During the landing phase of a plyometric jump, an athlete aims to minimize the impact forces on their joints. Which of the following strategies, from a kinetics perspective, would be most effective?