How much force would be required to lift a 350 Newton weight by using a pulley system with a mechanical advantage of 5?

Aplanet of mass m 6.75 x 1024 kg is orbiting in a circular path a star of mass m 2.75 x 1029 kg. the radius of the orbit is r 8.05 x107 km. what is the orbital period (in earth days) of the planet tplanet?

A23 kg log of wood begins from rest, 300 m up a sluice (a water track used to transport logs, think of it as an inclined plane with negligible friction) inclined at 20° to the horizontal. after it reaches the flat waterway at the bottom it collides elastically with a 100 kg block of wood initially at rest near the base of the incline. (a) how long does it take the 23 kg log to travel down the incline? (b) what is the speed of the 23 kg log at the bottom of the incline? (c) what are the velocities of both blocks of wood after the collision? (d) what is the total kinetic energy before the collision? (e) what is the kinetic energy of the 23 kg log after the collision? (f) what is the kinetic energy of the 100 kg block of wood after the collision? (g) what is the total kinetic energy after the collision? (h) compare the total initial and total final kinetic energies. is this consistent with what you would expect for elastic collisions? explain!

(science)study the following ocean currents map. an ocean currents map is shown. on the map the locations for san diego, california and savannah, georgia are marked. there is a looping current from the north past san diego and a looping current from the south near savannah which statement is most likely correct about the average temperatures in san diego, california as compared to savannah, georgia? it is higher in savannah because of the cool ocean currents from the south. it is higher in savannah because of the warm ocean currents from the north. it is lower in san diego because of the warm ocean currents from the south. it is lower in san diego because of the cool ocean currents from the north.