I believe it would be D. Electromagnet. It's been a while since I've done this stuff, tho. Hope this helps!!!! :)
Answer:
Physical changes
Explanation:
Changes in the state of matter are physical changes.
First, the material is made up of the same components that is was before it changed states.
The physical properties of the material changed, but its chemical composition did not, meaning that is is a physical change.
Answer:
B
Explanation:
Dalton worked with mainly about the chemistry of atoms.
how do atoms combine to form various molecules.
—rather than the details of the physical, internal structure of atoms, although he never denied the possibility of atoms' having a substructure.
answer: its 7290 joules.
explanations: the first procedure is to convert 1 pound to kilogram. 1 kg = 2.205 hence given 100 lb so we cross multiply. 1 kg * 100 = 2.205 * x
hence x= 45 kg. let's convert 1 mile per hour = 0.45 metre per second we cross multiply by 40 mile per hour. x= 40 * 0.45= 18 m/s.
KE= 1/2 * 45 * (18)^2
= 1/2 * 45 * 14580
= 7290joules
