A 5.00 kilogram block slides along a horizontal, frictionless surface at 10.0 meters per second. for 4.00 seconds. The magnitude of the blocks momentum is?

A) 200 Kg m/s

B) 50.0 Kg m/s

C) 20.0 Kg m/s

D) 12.5 Kg m/s

It's B. They are trying to trick you by adding the time so you would divide the speed by time, which then you multiply to 5 and get D's answer. Ignore the time. The time does not matter. just multiply 5 and 10 to get 50.