Which statement about convection in the Earth's mantle is true? A.
Convection contributes to the movement of the Earth's tectonic plates.
B.
Convection continuously cycles matter between the Earth's core and its crust.
C.
Convection causes the Earth's crust to be warmer than it otherwise would be.
D.
all of these

Two 2.0-cm-diameter disks face each other, 1.0 mm apart. they are charged to ±10 nc. what is the electric field strength between the disks? a proton is shot from the negative disk toward the positive disk. what launch speed must the proton have to just barely reach the positive disk?

Acamcorder has a power rating of 20 watts. if the output voltage from its battery is 9 volts, what current does it use?

Consider two less-than-desirable options. in the first you are driving 30 mph and crash head-on into an identical car also going 30 mph. in the second option you are driving 30 mph and crash head-on into a stationary brick wall. in neither case does your car bounce off the thing it hits, and the collision time is the same in both cases. which of these two situations would result in the greatest impact force?