A 50.0 kg boy jumps off the back of a 4.0 kg skateboard that is moving forward with an initial velocity of 3.0 m/s. Find the skateboard’s speed immediately after the boy jumps if the boy’s velocity when jumping off the back is 2.5 m/s in the forward direction.

Does anyone know how to solve this problem? i really need . i made an attempt but i just cant get it. a metal rod is 25.000 cm long at 25.0 degrees celsius. when heated to 102.0 degrees celsius, it is 25.054 cm long. what is the coefficient of linear expansion for this metal.

Two resistors r1 and r2 may be connected either in series or parallel across an ideal battery with emf ε. we desire the rate of energy dissipation of the parallel combination to be 8.75 times that of the series combination. if r1 = 105 ω, what are the (a) smaller and (b) larger of the two values of r2 that result in that dissipation rate?

The diagram shows four locations in the electric field of a positive point charge m. at which location is the electric potential the greatest.