When someone lifts a book from the ground, the work you use is positive. By lifting the book, you change it's energy and it's original place The book gains, kinectic energy.
Hope I helped.
Answer:
A physical change
Explanation:
You are wiping chalk particles from the board to the eraser which is just changing the location of the chalk particles, a physical change.
you're not changing the chalk into a new substance or causing a chemical reaction, which would be a chemical change.
Answer:
1
Explanation:
The ratio of their nuclear densities is 1, as nuclear density is constant for all nuclei.
Answer:
669042 N upward
Explanation:
= Work done by gravity on pile driver
= Work done by beam
u = Initial velocity
v = Final velocity
m = Mass of pile driver = 2200 kg
g = Acceleration due to gravity = 9.81 m/s²
h = Height the pile driver falls = 4.2 m
d = Bend in beam = 14 cm
Total work done = Change in Kinetic energy
The force the beam exerts on the pile driver while the pile driver is brought to rest is 669042 N upward
The fundamental closeness is they have a similar like charges repulse each other, distinctive charges pull in each other. While their distinction is that attractive "charges" can't be isolated. At any rate, so far it has not been accomplished. I trust this makes a difference.
