Answer:
Explanation:
Ok, the average speed can be calculate with the next equation:
(1)
Basically the car cover the same distance "d" two times, but at different speeds, so:
and the total time would be the time t1 required to go from A to B plus the time t2 required to go back from B to A:
From basic physics we know:
so:
Using the previous information in equation (1)
Factoring:
(2)
Finally, replacing the data in (2)
Answer:
B - The model does not move or behave like a real atom.
Explanation:
The solid ball does not show how the nucleus is composed of protons and neutrons, or the relationship between the electrons and the nucleus.
Answer:
20 N
Explanation:
In air, the normal force is equal to the weight.
∑F = ma
N − mg = 0
N = mg
Submerged in water, the normal force is equal to the weight minus the buoyant force:
∑F = ma
B + N − mg = 0
N = mg − B
Plugging in values:
80 N = 100 N − B
B = 20 N
Answer:
Explanation:
v = 50 km / h
= 13.89 m /s
When a vehicle runs on a circular path , it is static friction which prevents it from getting overturned .
static friction = μs mg
centripetal force = m v² / R
m v² / R = μs mg
R = v² / μs x g
= 13.89² / .7 x 9.8
= 28.12 m .
