Answer all questions.

Homework gubmigsion Rules: F'P'PP'P!' You are required to use either college ruled paper or grid paper for your homework. For all quantitative problems, show your work to receive a full credit. Put a box around your final answers and include proper units. Your nal answer should be presented in 2 decimal places. Take a picture of each of your answer sheets and save them in either PDF orJPEG format. Submit the pictures as attachments in iCollege Assignment. uggegd Problgm olving tratggy: P'P'PP'N!' Write down which variable you need to solve. List all known variables. Figure out which equations allow you to solve for the unknown from the known variables. Rearrange the equation to isolate the unknown variable. Plug in the known variables. {Steps 4 and S can be switched depending on your preference) Solve for the unknown variable. I. Calculations: (25 pts) 3. 1. John has a body mass of 90 kg and walks on three different surfaces. At heel strike the ground reaction force FE; is 160 N. Would he slip on (1) ice surface, (2) loose gravel, and (3) concrete? Given that [.15 is 0.15 for shoe-ice, 0.25 for shoe-loose gravel, and 0.75 for shoe-concrete. If he slips on any surfaces, list two suggestions that you would give him to prevent the slip. (S ptsj The diagram below shows the top view ofa baseball travelling in the air with clockwise rotation. Draw a diagram of airflow around this baseball. Label ALL areas around the ball {i.e., front, back, left, and right side) as either "high pressure\" or "low pressure\" {4ptsj. Also, draw the trajectory of the ball in flight, and explain why the ball does not follow a straight-line trajectory (1pt). John was swimming in the river. His swimming velocity was 0.7 m/s due east. The water was running at 0.1 m/s due west. John's projected area in the waterwas 0.45 ml. Water density was 1000 kg/m3. The coefficient of drag was 0.2. {a} What was John's velocity relative to the water? (b) What was the pressure drag force from the water? After a little while, John turned around and now is swimming at 0.7 m/s due west. {c} What is John's velocity relative to the water now? {d} What is the pressure drag force from the water now? (e) What is the percentage of change in pressure drag force? (Spts)