Answer:
- <em>Abbie’s acceleration is (1/2) Zak’s acceleration.</em>
Explanation
1. <u>Data</u>:
a) ω = constant
b) Abbie: r₁ = 1 m
c) Zak: r₂ = 2 m
d) Ac₁ = ? Ac₂
2. <u>Formulae</u>
3. <u>Solution</u>:
a) Abbie:
b) Zack:
c) Divide Ac₁ / Ac₂
- Ac₁ / Ac₂ = ω² (1m) / [ω² (2m) ] = 1/2
⇒ Ac₁ = (1/2) Ac₂ = Ac₂ / 2 = 0.5 Ac₂
Answer;
B. both a non-directional and directional hypothesis
Explanation;
A two-tailed test is the standard test of significance to determine if there is a relationship between variables in either direction. Two-tailed tests do this by dividing the .05 in two and putting half on each side of the bell curve.
A non-directional hypothesis is a type of alternative hypothesis used in statistical significance testing. In contrast, a directional alternative hypothesis specifies the direction of the tested relationship, stating that one variable is predicted to be larger or smaller than null value, but not both.
Answer:
A) 1568.60 Hz
Explanation:
This change is frequency happens due to doppler effect
The Doppler effect is the change in frequency of a wave in relation to an observer who is moving relative to the wave source
where
C = the propagation speed of waves in the medium;
Vr= is the speed of the receiver relative to the medium,(added to C, if the receiver is moving towards the source, subtracted if the receiver is moving away from the source;
Vs= the speed of the source relative to the medium, added to C, if the source is moving away from the receiver, subtracted if the source is moving towards the receiver.
A) Here the Source is moving towards the receiver(C-Vs)
and the receiver is standing still (Vr=0) therefore the observed frequency should get higher
Answer:
a. the time required for the onset of evaporation is: 196.1 seconds and b. the time required for all of the water to evaporate is: 1328.3 seconds.
Explanation:
We need to stablish that there is 3 states at this problem. At the firts one, water is compressed liquid and the conditions for this state are: P1=100KPa,T1=20°C,V1=0.5m^3. From the compressed liquid chart and using extrapolation, we can get: v1=vf1=0.0010018 (m^3/Kg) and u1=uf1=83.95(KJ/kg). Now we can find the mass of water at the state 1 as: 
Then the liquid water is heated at a rate of 0.85KW, and its volume increase, while work is done by the system at the boundary, we can assume that the pressure remains constant throughout the entire process. At the second state the water is saturated liquid and the conditions are: P2=100KPa, T2=Tsat=99.63°C, v2=vf2=0.001043(m^3/Kg) and u2=uf2=417.36(KJ/Kg). Now we can find the work as:
. (a) After that we need to do an energy balance for process 1-2 and get: U=Q-W or 
, solving for t we get the time required for the onset of evaporation:
.(b) Then continue heat transfer to the cooking pot and results in phase change getting vapor at 99.63°C. At the final state or third state the mass is zero because all liquid was evaporated and the initial mass at this state is the same for the second state: 0.5 (Kg) and doing an energy balances results in:
, but m3=0, now solving for t we can get the time required for all of the water to evaporate as:
. We can get from the saturated liquid chart the enthalpy he=hge=2675.5(KJ/Kg) @P=100KPa. Now we need to calculate the work related with the volume decreases as vapor exits the control volume or process 2-3 work boundary as: 
. Now replacing every value in the time equation we get:
Answer:
A. Normal force is always perpendicular to the area of contact between an object and support.
Explanation:
Normal force is defined as the contact force. If there is no contact between the surfaces, they cannot applies a force which is normal on each other. For e.g, the surfaces of a cubical box and the cart cannot applies a force of normal on each other because of no contact.
If, when there is a contact between two surfaces they applies a normal force on each other, and this force is perpendicular to the each other . This normal force is necessary to prevent object to penetrating into other.
