A disk rotates about its central axis starting from rest and accelerates with constant angular acceleration. At one time it is rotating at 9.80 rev/s; 80.0 revolutions later, its angular speed is 18.0 rev/s. Calculate (a) the angular acceleration (rev/s2), (b) the time required to complete the 80.0 revolutions, (c) the time required to reach the 9.80 rev/s angular speed, and (d) the number of revolutions from rest until the time the disk reaches the 9.80 rev/s angular speed.

For the car in the picture ,in which direction is the normal force? -into the screen -down -out of the screen -up

Your starship, the aimless wanderer, lands on the mysterious planet mongo. as chief scientist-engineer, you make the following measurements: a 2.50-kg stone thrown upward from the ground at 14.0 m/s returns to the ground in 5.70 s ; the circumference of mongo at the equator is 2.20×10^5 km ; and there is no appreciable atmosphere on mongo. (a) the starship commander, captain confusion, asks for the following information: what is the mass of mongo? (b) if the aimless wanderer goes into a circular orbit 2.20×10^4 km above the surface of mongo, how many hours will it take the ship to complete one orbit? (c) an unmanned spacecraft is in a circular orbit around the moon, observing the lunar surface from an altitude of 44.0 km . to the dismay of scientists on earth, an electrical fault causes an on-board thruster to fire, decreasing the speed of the spacecraft by 23.0 m/s . if nothing is done to correct its orbit, with what speed (in km/h) will the spacecraft crash into the lunar surface?

Which is not true of the intertropical convergence zone? a) it features heavy precipitation b) it's where the trade winds collidec) it's a high-pressure zone with sinking air d) it is also known as the doldrums