Kevin burns 5.5 cal/min by walking at a speed of 4.5 miles per hour. he is also able to have a conversation while performing this moderately intense physical activity. what effect does this activity have on his breathing and heart rate? a. a slight change in his breathing but no change in his heart rate b. no change in his breathing but a significant change in his heart rate c. a significant change in both his breathing and heart rate d. a slight increase in both his breathing and heart rate e. little to no change in his breathing and heart rate

Visualize the problem and identify special cases first examine the problem by drawing a picture and visualizing the motion. apply newton's 2nd law, ∑f⃗ =ma⃗ , to each body in your mind. don't worry about which quantities are given. think about the forces on each body: how are these consistent with the direction of the acceleration for that body? can you think of any special cases that you can solve quickly now and use to test your understanding later? one special case in this problem is if m2=0, in which case block 1 would simply fall freely under the acceleration of gravity: a⃗ 1=−gj^.