Who is doing work.

A Becky studies for her test. B Bob carries a baby across the hall C sally pushes a stroller around the block D Ben holds a plank for one minute

On the 1-to-10-billion scale, about how far is it to the nearest stars besides the sun? on the 1-to-10-billion scale, about how far is it to the nearest stars besides the sun?

What is the conservation of energy?

Which term describes the bending of a wave as it travels into a different medium? A. Reflection B. Interference C. Diffraction D. Refraction

Is the refraction different entering medium that has a higher index of refraction compared to entering amedium that has a lower index of refraction?

Which is a better conductor, metal or non metal

A hot-air balloon is ascending at the rate of 14 m/s and is 84 m above the ground when a package is dropped over the side. (a) How long does the package take to reach the ground? (b) With what speed does it hit the ground?

Now assume that the pitcher in Part D throws a 0.145-kgkg baseball parallel to the ground with a speed of 32 m/sm/s in the + x direction. The batter then hits the ball so it goes directly back to the pitcher along the same straight line.

How far away is a cliff if an echo is heard 0.486 s after the original sound? Assume that sound traveled at 343 m/s on that day.

Rafael swings a baseball bat with a force of 25 N. The baseball bat exerts a force of 5 N on the baseball. What is the mechanical advantage of the baseball bat? The mechanical advantage of the baseball bat is

Minerals such as sulfur can sometimes be identified by colors, true or false.