A spring, of spring constant k, is compressed by distance di, and when released pushes a block of mass m forward across a frictionless, horizontal surface. The block collides with another identical block which was initially at rest, and the two blocks stick together. What is the final speed of the combined system? A. di√2
B. di√k/2m
C. 2di√k/m
D. di/2√k/m

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.

Henry, whose mass is 95 kg, stands on a bathroom scale in an elevator. the scale reads 830 n for the first 2.4 s after the elevator starts moving, then 930 n for the next 2.4 s. part a what is the elevator's speed 4.8 s after starting? express your answer with the appropriate units.

In science and physics what is the standard unit of measure for speed?