Laws that implemented the consumers' right to be informed forbid misleading advertising.
Answer is C.
Answer:
a) 578.0 cm²
b) 25.18 km
Explanation:
We're given the density and mass, so first calculate the volume.
D = M / V
V = M / D
V = (6.740 g) / (19.32 g/cm³)
V = 0.3489 cm³
a) The volume of any uniform flat shape (prism) is the area of the base times the thickness.
V = Ah
A = V / h
A = (0.3489 cm³) / (6.036×10⁻⁴ cm)
A = 578.0 cm²
b) The volume of a cylinder is pi times the square of the radius times the length.
V = πr²h
h = V / (πr²)
h = (0.3489 cm³) / (π (2.100×10⁻⁴ cm)²)
h = 2.518×10⁶ cm
h = 25.18 km
Answer:
35.14°C
Explanation:
The equation for linear thermal expansion is 
, which means that a bar of length 
with a thermal expansion coefficient 
under a temperature variation 
will experiment a length variation 
.
We have then = 0.481 foot, = 1671 feet and = 0.000013 per centigrade degree (this is just the linear thermal expansion of steel that you must find in a table), which means from the equation for linear thermal expansion that we have a 
= 22.14°. As said before, these degrees are centigrades (Celsius or Kelvin, it does not matter since it is only a variation), and the foot units cancel on the equation, showing no further conversion was needed.
Since our temperature on a cool spring day was 13.0°C, our new temperature must be 
= 35.14°C
What do we know that might help here ?
-- Temperature of a gas is actually the average kinetic energy of its molecules.
-- When something moves faster, its kinetic energy increases.
Knowing just these little factoids, we realize that as a gas gets hotter, the average speed of its molecules increases.
That's exactly what Graph #1 shows.
How about the other graphs ?
-- Graph #3 says that as the temperature goes up, the molecules' speed DEcreases. That can't be right.
-- Graph #4 says that as the temperature goes up, the molecules' speed doesn't change at all. That can't be right.
-- Graph #2 says that after the gas reaches some temperature and you heat it hotter than that, the speed of the molecules starts going DOWN. That can't be right.
--
Answer:
v = 10 m/s
Explanation:
Let's assume the wheel does not slip as it accelerates.
Energy theory is more straightforward than kinematics in my opinion.
Work done on the wheel
W = Fd = 45(12) = 540 J
Some is converted to potential energy
PE = mgh = 4(9.8)12sin30 = 235.2 J
As there is no friction mentioned, the remainder is kinetic energy
KE = 540 - 235.2 = 304.8 J
KE = ½mv² + ½Iω²
ω = v/R
KE = ½mv² + ½I(v/R)² = ½(m + I/R²)v²
v = √(2KE / (m + I/R²))
v = √(2(304.8) / (4 + 0.5/0.5²)) = √101.6
v = 10.07968...
