Why must the cross-sectional area at the bottom of the sprue be less than the cross-sectional area at the top of the sprue during pouring

the answer is 100. i just did this lesson and got a 100% on it. : )

-fishtank

chemical energy --> gravitational potential energy --> kinetic energy --> elastic potential energy --> gravitational potential energy

explanation:

when emma starts the hike, the chemical energy stored in her body is used to climb up the mountain, and so she gains gravitational potential energy (because at the end, she will be at a higher height h above the ground). then she goes bungee jumping: as she falls, this gravitational potential energy is converted into kinetic energy (because her speed increases as she falls down), until the point when the rope stretches, and she stops moving. at that moment, all the kinetic energy is converted into elastic potential energy due to the stretching of the rope. then, this energy is released because the rope returns to its natural length, and emma gains a small increase in altitude , so she gains some gravitational potential energy.

well, their are quite a few differences !

explanation:

first difference is a main sequence star is made of carbon, while a neutron star is made of neutrons. another difference is a main sequence star still has hydrogen to burn, while a neutron star is a remnant of a supernova.

a main sequence star is what’s left over from a low-mass star death, while a neutron star is what’s left from the death of a high-mass star. main sequence star and a neutron star are considered the same thing, except a main sequence star spins.