Phy help!

An equilateral triangle 10.0m on a side has a 1.00-kg mass at one corner, a 2.00-kg mass at another corner, and a 3.00-kg mass at the third corner. Find the magnitude of the net force acting on the 1.00-kg mass. Find the direction of the net force acting...

The pistons in an internal combustion engine undergo a motion that is approximately simple harmonic. If the amplitude of motion is 3.8cm , and the engine runs at 1500rpm , find the maximum acceleration of the pistons. Find their maximum speed.