The friction force depends on the surface the block is sliding (slippery or rough) and the normal force on the block which is the force of gravity. The image above shows a block pulled across a table. The spring scale which measures in Newtons reads the force resisting the motion known as friction force. In the image above, what would be a reasonable measurement of normal force if friction force measured 80 Newtons?

A) 40 Newtons
B) 60 Newtons
C) 70 Newtons
D) 140 Newtons

Sawyer is studying diffraction. he draws a diagram of a plane wave to show how light waves travel. which best describes sawyer’s error? the wave fronts should be perpendicular to the direction in which the waves move. the arrow showing the direction of movement of the waves should be pointing to the left. the arrow showing the direction of movement of the waves should be pointing downward. the wave fronts should be both parallel and perpendicular to the direction in which the waves move.

The star betelgeuse is about 600 light-years away. if it explodes tonight, a. we'll know because debris from the explosion will rain down on us from space.b. we'll know it immediately because it will be brighter than the full moon in the sky.c. we won't know about it until 600 years from now.d. none of the above.

Which is a substance that can be separated by physical means and is not the same throughout