The area of the circle with radius r is
A = πr²
The rate of change of area with respect to time is

The rate of change of the radius is given as

Therefore

When r = 10 ft, obtain

Answer: - 40π ft²/s (or - 127.5 ft²/s)
Answer:
The correct answer is: b. Channel
Explanation:
The Communication Process Model (CPM) is a model that describes the steps through which effective exchange of information takes place from the sender of a message to the receiver(s) of the message. (Refer to attached image)
The CPM includes the following steps:
1. Noise- reducing physical/ physiological distractions that can impede clear communication.
2. Communicator- the person who initiates the communication
3. Message- the information exchanged between the sender and receiver of the message
4. Feedback- How the information from the sender is received by the recipient of the communication
5. Channel- The medium by which the information is delivered from the sender to the receiver.
In this instance, when Aaden decided to have a discussion with his significant other in his home using face-to-face communication, he is deciding on the channel or medium through which the communication will this place. By choosing face-to-face communication at his home, Aaden has determined what he believes is the most appropriate context for the conversation with his significant other, given the sensitive nature of the topic. In this way, Aaden has selected a channel of communication.
Answer:
a = 1.16 m/s²
Explanation:
In order to find the acceleration of the ball we will use 3rd equation of motion.
2as = Vf² - Vi²
where,
a = acceleration = ?
s = displacement = 21.9 m
Vf = Final Velocity = 7.14 m/s
Vi = Initial Velocity = 0 m/s (Since, ball starts from rest)
Therefore, using the values, we get:
2a(21.9 m) = (7.14 m/s)² - (0 m/s)²
a = (50.97 m²/s²)/(43.8 m)
<u>a = 1.16 m/s²</u>
The kinetic energy of the wind ==> causes ==>
the windmill to turn (mechanical energy) ==>
which is used to turn an electric generator ==>
which generates electrical energy.
Answer:
K.E = 30,000 J
Explanation:
Given,
The potential energy of the roller coaster car, P.E = 40000 J
The kinetic energy at height h/4, K.E = ?
According to the law of conservation of energy, the total energy of the system is conserved.
At height 'h', the total energy is,
P.E = mgh
K.E = 0
At height 'h/4', the total energy is
P.E + K.E = mgh
P.E = mgh/4
K.E = 1/2 mv²
Therefore,
mgh/4 + 1/2 mv² = mgh
gh/4 + v²/2 = gh
Hence,
v² = 3gh/2
Substituting in the K.E equation
K.E = 1/2 mv²
= 1/2 m (3gh/2)
= 3/4 mgh
= 3/4 x 40000
= 30000 J
Hence, the K.E of the roller coaster car is, K.E = 30000 J