Answer:
3. all of the above
4. d=m/v
5. gas has well separated particles with no particular arrangement
liquid has particles close together but still with no particular arrangement
and solid has particles that are tightly packed, usually in a regular pattern
6. (idk what number it is but)
the density of the rock is 2.4 g/ml
d=m/v so d=12/v according to the question the mass is 12
to find volume subtract 20-15 because before the rock was 15 and after the rock was 20, so then you get 5 for volume
d=12/5 and when you calculate that, you would get 2.4g/ml ; hope this helped :-)
A the entropy of the reaction I think ion know if that’s correct
As our story begins, the sled ... whose mass is 8 kg ... is sliding along the ice at a speed of 4 m/s.
The sled's kinetic energy is (1/2 m v²) = (4 kg · 16 m²/s²) = 64 J .
After what seems like only the blink of an eye, the sled is no longer sliding. It is stationary. Motionless. At Rest. Just sitting there !
Its speed has been reduced to zero and ... because kinetic energy is the energy of motion ... the sled's kinetic energy is now also zero. Sixty-four Joules of energy have disappeared !
How can this be ? ! ? We know that energy is conserved. It can never just appear out of nothing, and it can never just disappear into nothing. If energy suddenly appears, it had to come from somewhere, and if energy suddenly disappears, it had to go somewhere. So where did our 64 Joules of kinetic energy go ?
It went into the ice, THAT's where ! We can say that the sled did 64J of work, and melted a thin slick layer of water on the surface of the ice. OR we can say that friction did NEGATIVE 64J of work on the sled, to cancel the 64J that it had originally, sap its kinetic energy, and bring it to rest.
I think <em>choice-B</em> was supposed to say "<em>B. -64J</em>", but somebody typed it sloppily and neglected to proofread it before posting.
