which of the following drives the movement of convection currents

A. pressure differences

B. density differences

C. volume differences

Why does an empty plate not heat up in the microwave?

The earth takes 1 year to revolve around the sun at 1 A. U. distance (an astronomical unit = 93,000,000 miles). If a planet were 4 A. U. from the sun, how many years would it take to make 1 orbit?

As more bulbs are added to a series circuit what happens to the resistance of the circuit

How many moles of MgCl2 are there in 315 g of the compound? mol

A positively charged particle initially at rest on the ground accelerates upward to 140 m/s in 2.10 s. The particle has a charge-to-mass ratio of 0.100 C/kg and the electric field in this region is constant and uniform.

A car is moving with a speed of 22 m/s. The driver then brakes, and the car comes to a halt after 6.5 s. What is the distance covered by the car after the driver brakes, until it comes to a stop? A) 36 m B) 72 m C) 140 m D) 210 m

Which of the following best explains why an explosive charge in a cannon can cause a cannonball to fly out of the cannon with a high velocity? A. because chemical potential energy can convert to gravitational potential energy B.

Distance divided by time what is velocity

The decay constant of a radioactive nuclide is 4.6 x 10^-3 s^-1. What is the half-life of the nuclide? 2.5 min 2.0 min 1.4 min 3.6 min 3.1 min

A furlong is an old british unit of length equal to 0.125 mi, derived from the length of a furrow in an acre of ploughed land. a fortnight is a unit of time corresponding to two weeks, or 14 days and nights.