A 50 kg student stands on a 4 kg skateboard at rest. The student catches a 9 kg backpack moving with a horizontal speed of 2 m/s in the direction the skateboard is free to roll. How fast will the student and the skateboard move after catching the backpack, assuming friction is negligible? Round your final answer to the hundredths place.

If 2 moles of co_2 at 2l and 500k are expanded reversibly to 20l, more work can be obtained from an adiabatic process than from an isothermal process. is the above statement true or false?

Ascientific blank must be testable and capable of being proven false?

Large electric fields in cell membranes cause ions to move through the cell wall. the field strength in a typical membrane is 1.0 x 10 7 n/c. what is the magnitude of the force on a calcium ion with charge +e? what is its acceleration? is it possible for a particle with the same charge as as calcium to have a different acceleration if placed at this location? what would change the acceleration: mass of the particle? diameter of the particle?