Answer:
(a) t = 22.9 s
(b) α= - 0.467 rad/s²
Explanation:
The uniformly accelerated circular movement, is a circular path movement in which the angular acceleration is constant.
We apply the equations of circular motion uniformly accelerated :
ωf ²= ω₀² + 2*α*θ Formula (1)
ωf= ω₀ + α*t Formula (2)
Where:
θ : angle that the body has rotated in a given time interval (rad)
α : angular acceleration (rad/s²)
t : time interval (s)
ω₀ : initial angular speed ( rad/s)
ωf : final angular speed ( rad/s)
Data
θ = 19.5 revolutions : angular displacement of each wheel or angle that the wheel has rotated in a given time interval
ω₀= 10.7 rad/s : initial angular speed of the Wheel ( rad/s)
ωf = 0 : final angular speed of the Whee( rad/s)
Calculating of the angular acceleration (α )
We replace data in the fómula (1),considering that 1 revolution is equal to 2π radians :
ωf ²= ω₀² + 2*α*θ
(0 )²= (10.7)² + 2*α*(19.5*2*π )
0= 114.49 + (245.04)*α
-114.49 = (245.04)*α
α= (-114.49) /(245.04)
α= -114.49 /(245.04)
α= -0.467 rad/s²
Time does it take for the bike to come to rest
We replace data in the formula (2)
ωf = ω₀ + α*t
0 = 10.7 + -0.467*t
-10.7 = - 0.467*t we multiply by (-1) both sides of the equation :
10.7 = 0.467*t
t = 10.7 / 0.467
t = 22.9 s
The Ideal Gas Law makes a few assumptions from the Kinetic-Molecular Theory. These assumptions make our work much easier but aren't true under all conditions. The assumptions are,
1) Particles of a gas have virtually no volume and are like single points.
2) Particles exhibit no attractions or repulsions between them.
3) Particles are in continuous, random motion.
4) Collisions between particles are elastic, meaning basically that when they collide, they don't lose any energy.
5) The average kinetic energy is the same for all gasses at a given temperature, regardless of the identity of the gas.
It's generally true that gasses are mostly empty space and their particles occupy very little volume. Gasses are usually far enough apart that they exhibit very little attractive or repulsive forces. When energetic, the gas particles are also in fairly continuous motion, and without other forces, the motion is basically random. Collisions absorb very little energy, and the average KE is pretty close.
Most of these assumptions are dependent on having gas particles very spread apart. When is that true? Think about the other gas laws to remember what properties are related to volume.
A gas with a low pressure and a high temperature will be spread out and therefore exhibit ideal properties.
So, in analyzing the four choices given, we look for low P and high T.
A is at absolute zero, which is pretty much impossible, and definitely does not describe a gas. We rule this out immediately.
B and D are at the same temperature (273 K, or 0 °C), but C is at 100 K, or -173 K. This is very cold, so we rule that out.
We move on to comparing the pressures of B and D. Remember, a low pressure means the particles are more spread out. B has P = 1 Pa, but D has 100 kPa. We need the same units to confirm. Based on our metric prefixes, we know that kPa is kilopascals, and is thus 1000 pascals. So, the pressure of D is five orders of magnitude greater! Thus, the answer is B.
The mode in this case would be 125 because it occurs the most in the sequence of numbers.
Well her speed and velocity are the same 8 kilometers per hour<span />
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