Agirl pulls her younger brother on a sled along a flat sidewalk (the total mass of the sled is 30kg). a frictional force of 50n opposes the pull. when moving, the girl pulls on the sled with a force of 150n at an angle of 30 degrees.

how much time will it take for the sled to travel 50?

what is the normal force?

Astone is thrown into a pond. what happens to the amplitude of the resulting waves as they get farther from the point where the stone hit the water? explain.

30 points - when can a theory be modified if a new type of technology allows for new observations that raise new questions? a. immediately, while the questions about the theory are being asked b. after new hypotheses related to the theory are tested in experiments c. only after the new observations disprove all parts of the theory d. while scientists begin to think about how the theory could improve

Imagine you are standing in the antarctic during the southern hemisphere summer. the sky is clear and blue. there are no clouds in the sky. your shadow is cast on the icy ground. what is the color of the shadow?