A tennis ball is hit by a tennis racket, which imparts a force on the ball that varies in time according to F(t) = 30 sin(5лt) [N]. Calculate the impulse on the ball from t=0 sec to t = 0.2 sec.

Consider a person serving a platter of hot food to their family who is gathered around a table. When holding theplatter, the person can choose how to hold the platter in front of them and would like compare the differences between position 1 and position 2 as shown below. In position 1, the shoulder is at 0 degrees while the elbow is at 90 degrees and in position 2, the arm is flexed as shown.   a.) Consider the elbow joint and draw free body diagrams for each of the positions shown, including gravitational forces (consider the weight of the combined forearm and hand), elbow flexor forces, and the joint contact force.  b.) Use the information provided below to solve for the magnitude of the elbow flexor force (in Newtons) for positions 1 and 2, the magnitude of the joint contact force (in Newtons), and the angle that the joint contact force makes with respect to the horizontal axis. • The platter of food weighs 7 lbs; the person weighs 175 lbs, and the person is 5’8” tall. • θ = 130…

The force of friction depends on the two materials in contact and: Group of answer choices The amount of surface area in contact Normal force

Anything I need to add to this free body diagram are the congruency marks appropriate?