Which of the following situations describes static friction? a. A heavy crate standing on a rough patch of mud and is being push
ed by two workers, but they cannot get it to move b. A large piano resting on a sheet of ice is being pushed by a child, but the child is not strong enough to get it to move
The answer is A because the weight of the crate is sitting on something rough. The roughness is going to resist anything that tries to move against it because the force being exerted by the 2 workers is not strong enough to get the crate to move out of its place on the mud since it's static.
The answer can't be B because ice is smooth and doesn't have any friction, the little girl can't move it because it's to heavy for her to move, not because there's friction acting against it.
Running for 300 m at 3 m/s takes 100 seconds and running at 300 m at 6 m/s takes 50 seconds. 100 s + 50 s = 150 s (total time). Total distance is 600 m, so 600 m/ 150 s = 4 m/s.
