Aplane heading due east with a velocity of 450 km/hr encounters a strong wind heading 20 degrees north of west with a velocity of 67 km/hr. what is the ground velocity of the plane.

Two particles of masses m and 2m are placed on a smooth horizontal table. a string, which joins these two masses, hangs over the edge supporting a pulley, which suspends a particle of mass 3m.the pulley has negligible mass. the two parts of the string on the table are parallel and perpendicular to the edge of the table. the hanging parts of the string are vertical. find the acceleration of the particle of mass 3m.

Power can be defined as a. the distance over which work was done. b. how much work can be done in a given time. c. all the work in an given area. d. the energy required to do work.

Anybody wanna ? (picture included? )