Introduction to Simple Machines
This activity will help you meet this educational goal:
You will compare and contrast information from a video with information from a text.
Directions
Read the instructions for this self-checked activity. Type in your response to each question, and check your answers. At the end of the activity, write a brief evaluation of your work.
Activity
Watch this video and then answer the following questions based on what you learned.
Part A
How does a bicycle make work easier?
Part B
Which two examples of levers are mentioned in the video?
The picture shows a bicycle’s pedals. Look at the shaft that the pedals are attached to. Do you think the shaft is a lever? Why or why not?
Answer:
word for word answers!
Explanation:
1) Part A: By pedaling a bicycle lightly, the rider can go a long way
2) Part B: The two examples mentioned in the video are the handlebars and the brakes
3) Yes, it’s a type of lever because the two pedals rotate around a fixed point
Which change in an object would increase the force needed to move the object?
А.
decreasing the velocity of an object
B
increasing the volume of an object
с
decreasing the mass of an object
D
increasing the mass of an object
Answer:
D i think
Explanation:
Heavier objects (objects with more mass) are more difficult to move and stop.
Answer:
Increasing the mass of the object (option D in the list of answers)
Explanation:
Recall that F = m x a
therefore, if the mass increases, the force increases
One of the harmonics of a column of air in a tube that is open at both ends has a frequency of 448 Hz, and the next higher harmonic has a frequency of 576 Hz. What is the fundamental frequency of the air column in this tube?
Answer:
The fundamental frequency is [tex]f_1 =128 \ Hz[/tex]
Explanation:
From the question we are told that
The frequency of one harmonics is [tex]f_x= 448 \ Hz[/tex]
The next higher harmonic is [tex]f_z = 576 \ Hz[/tex]
Generally the frequency of an air column open at both ends is mathematically represented as
[tex]f_n = \frac{nv }{ 2 L }[/tex]
Here n is the order of the harmonics (frequency)
v is the velocity of the sound
L is the length of the column
So for one harmonics we have that
[tex]f_k = \frac{n v }{2L}[/tex]
Then for the next higher harmonics
[tex]f_x = \frac{n+1 ) v}{2 L }[/tex]
Generally the difference between these frequencies is mathematically represented as
[tex]f_z- f_x = \frac{(n+1 )v}{ 2L} - \frac{(n )v}{ 2L}[/tex]
=> [tex]576 - 448 = \frac{vn + v - nv }{2L}[/tex]
=> [tex]\frac{ v }{2L} = 128[/tex]
Generally for fundamental frequency n = 1
So
[tex]f_1 = n * \frac{v}{2L}[/tex]
So
[tex]f_1 =1 * 128[/tex]
=> [tex]f_1 =128 \ Hz[/tex]
A certain heat engine does 30.2 kJ of work and dissipates 9.14 kJ of waste heat in a cyclical process.
A) What was the heat input to this engine?
B) What was its efficiency?
Answer:
a) [tex]H_{in}=39.34 kJ[/tex]
b) Efficiency=76.77%
Explanation:
a)
In order to solve this problem, we can use the following formula:
[tex]H_{in}=H_{out}+W[/tex]
the problem provides us with all the necessary information so we can directly use the formula:
[tex]H_{in}=9.14kJ+30.2kJ[/tex]
[tex]H_{in}=39.34 kJ[/tex]
b) In order to find the efficiency, we can use the following formula:
[tex]Efficiency=\frac{W}{H_{in}}*100\%[/tex]
so we get:
[tex]Efficiency=\frac{30.2kJ}{39.34kJ}*100\%[/tex]
Efficiency=76.77%
How long does it take a plane, traveling at a constant speed of 123 m/s, to fly once around a circle whose radius is 4330 m?
Answer:
3.7 minExplanation:
Step one:
given data
speed = 123m/s
radius of circle= 4330m
Step two:
We need to find the circumference of the circle, it represents the distance traveled
C=2πr
C= 2*3.142*4330
C= 27209.72m
Step three:
We know that velocity= distance/time
time= distance/velocity
time= 27209.72/123
time=221.2 seconds
in minute = 221.2/60
time= 3.7 min
which of the following is true of phototsythesis but not of cellular respiration.
A- Photosynthesis releases oxygen gas as a product
B- Photosynthesis occurs in all organisms
C- Photo synthesis is a process in which glucose i broken down
D- Photosynthesis requires glucose as a reactant
Answer:
B. Photosynthesis occurs in all organisms
Hope this helps!! :)
A statement of the second law of thermodynamics is that:__________.
a) spontaneous reactions are always exothermic.
b) energy is conserved in a chemical reaction that has a decrease in entropy.
c) spontaneous reactions are always endothermic.
d) in a spontaneous process, the entropy of the universe increases.
Answer:
in a spontaneous process, the entropy of the universe increases.
Explanation:
Entropy is a measure of of the degree of randomness or disorderliness in a system.
The second law of thermodynamics can be stated as follows; "in any spontaneous process, the entropy of the universe increases."
The universe here refers to the system's disorder and the disorder of the surroundings. Therefore, a spontaneous process can occur, in which the entropy of the system decreases, only if the entropy increases in the surroundings.
For instance, when ice freezes, the entropy of liquid water decreases, that is, the entropy of the system decreases. However, heat is given off to the surroundings and the entropy of the surroundings increases. This is an obvious expression of this law.
The glowing dot represents the transmission of a nerve impulse along the nerves that make up the neural pathway. A nerve impulse is an electrical signal that travels from one nerve cell to another.
Which part of the brain processes this signal?
Answer:
The answer is "Cerebral Cortex"
Explanation:
The neurotransmitter diffuses across the short distance of the synapse and ties to a receptor protein of the objective neuron. At the point when the sub-atomic sign ties to the receptor, the cell film of the objective neuron changes its electrical state and another evaluated expected starts. On the off chance that that evaluated potential is sufficiently able to arrive at limit, the subsequent neuron produces an activity potential at its axon hillock. The objective of this neuron is another neuron in the thalamus of the mind, the piece of the CNS that goes about as a transfer for tactile data.
At another neurotransmitter, synapse is delivered and ties to its receptor. The thalamus at that point sends the sensory information to the cerebral cortex, the furthest layer of dark issue in the brain, where cognizant view of that water temperature starts.
A region of the cortex is particular for imparting signs down to the spinal cord for development. The upper engine neuron is in this area, called the precentral gyrus of the frontal cortex, which has an axon that broadens right down the spinal cord. At the degree of the spinal cord at which this axon makes a neurotransmitter, a reviewed potential happens in the cell membrane of a lower engine neuron.
