Why energy must be added to a solid to cause it to melt.

The astronauts on the space shuttle flights experienced an acceleration of 29 m/s2 (about 3 "g's") during lift-off. what upward force must the astronaut's seat apply to the astronaut in order to cause this acceleration? assume the astronaut's mass is 70 kg, and compute this force when the acceleration is near the earth's surface so their weight equals latex: mg m g .

Which planet do you think would be easiest for humans to colonize some day?

Which describes an object in projectile motion? check all that apply.a.gravity acts to pull the object downb.the object moves in a straight path.c.the forward velocity of the object is 0 m/s.d.the object’s inertia carries it forward.e.the path of the object is curved.