The graph shows vertical displacement of the center of mass over 1 second for two gymnastics skills. Based on the graph, what does Skill B’s centre of mass trajectory indicate compared with Skill A?

Using the graph of momentum before and after a collision on different surfaces, which surface shows the greatest decrease in momentum during the collision?

A sports science lab analyzed the first second of sprint acceleration for an elite 100m sprinter. Using a force plate and motion capture, they recorded velocity, net horizontal force, and impulse values in 0.2s intervals. Data are presented in Figure 1 and Figure 2. Impulse was calculated as the product of force × time, and velocity data were used to calculate acceleration and momentum changes. The purpose was to evaluate the sprinter’s ability to apply force efficiently during the start phase using biomechanical principles.

Figure 1: Velocity of Sprinter Over First Second

Figure 2: Net Force and Impulse During the First Second

What concept is illustrated when a gymnast pushes down on a trampoline and it propels her upward?

An Olympic weightlifter applies a constant upward force of $1750\text{ N}$ to a barbell with a mass of $140\text{ kg}$. Take $g=10\text{ m s}^{-2}$, so the weight of the barbell is . What is the magnitude of the barbell's acceleration at the instant the force is applied?