Two adjacent students stand on stationary skateboards, face each other, and push apart. The skateboarder on the left weighs 55 kg, the one on the right is
65 kg. If the lighter skateboarder moves at 4.2 m/s, determine the speed and
direction of the heavier skateboarder.

What happens in a global convection cell

Aprojectile is launched from ground level with an initial velocity of v 0 feet per second. neglecting air resistance, its height in feet t seconds after launch is given by s equals negative 16 t squared plus v 0 t. find the time(s) that the projectile will (a) reach a height of 192 ft and (b) return to the ground when v 0equals112 feet per second. (a) find the time(s) that the projectile will reach a height of 192 ft when v 0equals112 feet per second. select the correct choice below and, if necessary, fill in the answer box to complete your choice.

Matter is needed to transfer thermal energy bya. conductionb. convectionc. radiation d. both a & b.