Question

a tennis player uses ______ in the arm to cause acceleration of the tennis ball. a balance b deceleration c friction d velocity
pregunta 2 (3 puntos) (02.02 mc)
joshua is warming up for his baseball game. he includes practice swings, throwing the ball, and lunges in his warm - up. which of the following does he need to add for a complete warm - up? a a deep breathing exercise b an aerobic exercise c a muscle - stretching exercise d a sport - specific exercise
pregunta 3 (3 puntos) (02.02 mc)
which of the following shows the best example of a cool - down activity? a jumping rope b walking c climbing stairs d lifting weights
pregunta 4 (3 puntos) (02.02 mc)
charli is a skilled gymnast at her local gym. in which of the following sports would she receive the most benefit from her gymnastics skills? a diving b basketball c lacrosse d tennis

Explanation:

1. A tennis player uses force to accelerate the ball. Among the options, none are directly related to the force - generating concept for acceleration, but friction between the racket and the ball helps in controlling the ball's motion during acceleration. Balance is more about stability, deceleration is the opposite of acceleration, and velocity is the rate of change of position.
2. A complete warm - up routine should include muscle - stretching exercises to prepare the muscles for activity, in addition to dynamic movements like practice swings, throwing, and lunges. Deep breathing can be part of relaxation, aerobic exercise is more of a main activity, and he already has sport - specific exercises.
3. Walking is a gentle activity that helps in gradually reducing the heart rate and blood pressure after exercise, making it a good cool - down activity. Jumping rope, climbing stairs, and lifting weights are more intense and not ideal for cooling down.
4. Gymnastics skills such as balance, flexibility, and body control are highly beneficial in diving, where similar skills are required for executing dives and maintaining form in the air and water. Basketball, lacrosse, and tennis have different primary skill requirements.

Answer:

1. c. friction
2. c. A muscle - stretching exercise
3. b. Walking
4. a. Diving