Answer:
v = 13.19 m / s
Explanation:
This problem must be solved using Newton's second law, we create a reference system where the x-axis is perpendicular to the cylinder and the Y-axis is vertical
X axis
N = m a
Centripetal acceleration is
a = v² / r
Y Axis
fr -W = 0
fr = W
The force of friction is
fr = μ N
Let's calculate
μ (m v² / r) = mg
μ v² / r = g
v² = g r / μ
v = √ (g r /μ)
v = √ (9.8 11 / 0.62)
v = 13.19 m / s
Answer: The correct answer is "the pitch drops to a lower pitch once the ambulance passes by Juan".
Explanation:
Doppler effect is the phenomenon in which there is an increase or decrease in the frequency when there is relative motion between the source and listener.
Pitch depends on the frequency. if the frequency increases then pitch increases.
When the source and the listener are moving towards each other then there is increase in the frequency. When the source and the listener are moving away each other then there is decrease in the frequency.
In the given problem, Juan is standing on the street. An ambulance moves toward him and then passes by the pitch drops to a lower pitch once the ambulance passes by Juan.
Answer:
285 seconds
Explanation:
Jenny speed is 3.8 m/s
Alyssa speed in 4.0 m/s
Alyssa starts after 15 seconds
Find the distance covered by Jenny, when Alyssa starts
Distance=Speed*time
Distance covered by Jenny in 15 seconds= 3.8×15=57m
Relative speed of the two members heading same direction will be;
4.0m/s-3.8m/s=0.2m/s
To find the time Alyssa catch up with Jenny you divide the distance to be covered by Alyssa by the relative speed of the two
Distance=57m, relative speed=0.2m/s t=57/0.2 =285 seconds
=4.75 minutes
Answer:
The average rate of energy transfer to the cooker is 1.80 kW.
Explanation:
Given that,
Pressure of boiled water = 300 kPa
Mass of water = 3 kg
Time = 30 min
Dryness friction of water = 0.5
Suppose, what is the average rate of energy transfer to the cooker?
We know that,
The specific enthalpy of evaporate at 300 kPa pressure


We need to calculate the enthalpy of water at initial state


We need to calculate the enthalpy of water at final state
Using formula of enthalpy

Put the value into the formula


We need to calculate the rate of energy transfer to the cooker
Using formula of rate of energy

Put the value into the formula


Hence, The average rate of energy transfer to the cooker is 1.80 kW.
<span>Answer:
Correct answer is
just add the two kinetic energies;
E = (1/2)mv^2 + (1/2)mv^2</span>