Answer: the density changed, the salt dissolved in the water, the salt and the water can still be separated into their individual molecules.
Explanation: physical changes are changes in size, shape, or state. Another way to think about a physical change is any change not involving a change in the substance’s chemical identity. You cannot write a chemical equation for salt water because the chemical identity is still salt AND water
trust me i did it
Answer:
Wegener first thought of this idea by noticing that the different large landmasses of the Earth almost fit together like a jigsaw puzzle. The continental shelf of the Americas fits closely to Africa and Europe, and other continents showed the same trend. Wegner also analyzed both sides of the Atlantic Ocean for rock type, geological structures and fossils and noticed that there was a significant similarity between matching sides of the continents, especially in fossil plants.
Answer:
adapted from NOVA, a team of historians, engineers, and trade experts recreate a medieval throwing machine called a trebuchet. To launch a projectile, a trebuchet utilizes the transfer of gravitational potential energy into kinetic energy. A massive counterweight at one end of a lever falls because of gravity, causing the other end of the lever to rise and release a projectile from a sling. As part of their design process, the engineers use models to help evaluate how well their designs will work.
Explanation:
Speed is scalar, meaning it's only going to be like 74 mph, doesn't matter which direction. Velocity is a vector, meaning it has direction. You can go -74mph when talking about velocity, not speed.
Answer:
184 feets
Explanation:
Given the data:
time (sec) __ velocity (ft/sec)
0 __________30
1 __________ 54
2 __________56
3 __________34
4 __________ 8
5 __________ 2
6 __________22
Using left end approximation:
(0,1) ___ f(0) = 30
(1,2) ___ f(1) = 54
(2,3) ___f(2) = 56
(3,4) ___f(3) = 34
(4,5) ___f(4) = 8
(5,6) __ f(5) = 2
Hence, the Total distance traveled during the 6 second interval is:
Change ; dT = 1
1 * (30 + 54 + 56 + 34 + 8 + 2) = 184
