C. I took the test...........
Distance between the two cars is increasing at the rate of 85 mph.
A passenger in Car-1 says that he is at rest in his own frame of reference,
and Car-2 is moving away from him at 85 mph, toward the west.
Answer:
B. Marginal cost equals long-run average total cost.
Explanation:
The zero profit condition implies that entry continues until all firms are producing at minimum long run average total cost. Since the marginal cost curve cuts the long run average total cost curve at its minimum point, marginal cost and long run average total cost must be equal in long run equilibrium.
Answer:
a)
b)
c)
d)
m
e)λ=∞
Explanation:
De Broglie discovered that an electron or other mass particles can have a wavelength associated, and that wavelength (λ) is:

with h the Plank's constant (
) and P the momentum of the object that is mass (m) times velocity (v).
a)

b)

c)

d)
m
e) 
λ=∞
Answer:
The height is 3.1m
Explanation:
Here we have a conservation of energy problem, we have a conversion form eslastic potencial energy to gravitational potencial energy, so:

then we have only gravitational potencial energy when the ball is at its maximun height.

because all the energy was transformed Eg=Ee

searching the web, the mass of a ping pong ball is 2.7 gr in average. so:
