Explanation:
Displacement= 600 m
Time= 5×60 = 300 sec
Velocity= Displacement/time
= 600/300
= 2 m/s
Greg can't remember how tall his 9-month-old niece is. He guesses that she is 100 cm tall. Which of the following is true?
Age (months)
Height (cm)
3 61.1
6 67.8
9 72.3
12 76.1
A.
Based on the data, Greg's guess is reasonable.
B.
Based on the data, Greg's guess is not reasonable.
C.
Based on the data, Greg's niece should be around 61.1 cm tall.
D.
Based on the data, Greg's niece should be around 76.1 cm tall.
Answer:
C
Explanation:
A music fan at a swimming pool is listening to a radio on a diving platform. The radio is playing a constant- frequency tone when this fellow, clutching his radio, jumps off. Describe the Doppler Effect heard by (a) a person left behind on the platform and (b) a person down below floating on a rubber raft. In each case, specify (1) whether the frequency is greater or smaller than the frequency produced by the radio, (2) whether the observed frequency is constant, and (3) how the observed frequency changes during the fall, if it does change. Give your reasoning.
Answer:
The Doppler Effect is given by the following relation;
[tex]f' = \left (\dfrac{v + v_0}{v - v_s} \right) \times f[/tex]
Where;
f' = The frequency the observer hears
f = Actual frequency of the wave
v = The velocity of the sound wave
[tex]v_o[/tex] = The velocity of the observer
[tex]v_s[/tex] = The velocity of the source
Where the observer is stationary, we have;
(i) When the source is moving in the direction of the observer
[tex]f' = \left (\dfrac{v }{v - v_s} \right) \times f[/tex]
(ii) When the source is receding from the observer, we have;
[tex]f' = \left (\dfrac{v }{v + v_s} \right) \times f[/tex]
Therefore;
(a) A person left behind on the platform
For a person left behind on the platform, we have that the radio source is receding, therefore, we have;
[tex]f' = \left (\dfrac{v }{v + v_s} \right) \times f[/tex]
(1) Given that (v + [tex]v_s[/tex]) > v, therefore, v < (v + [tex]v_s[/tex]), f' < f, the frequency heard by the person left on the platform, f', is smaller (lower) than the frequency produced by the radio
(2) The frequency is not constant as the speed of the source is increasing while it under the acceleration due to gravity
(3) During the fall, the speed of the source continuously increases under the effect of gravitational attraction and therefore the frequency heard by the person on the platform becomes progressively smaller
(b) A person down below floating on a rubber raft
For the the person down below on the rubber raft, the radio source is advancing
Therefore, the radio source is moving towards the person at rest down on the rubber raft, therefore, we have;
[tex]f' = \left (\dfrac{v }{v - v_s} \right) \times f[/tex]
(1) Given that (v - [tex]v_s[/tex]) < v, therefore, f' > f, the frequency heard by the person down below floating on the rubber raft, f', is greater (higher) than the frequency produced by the radio
(2) The frequency is not constant as the speed of the source is increasing while it under the acceleration due to gravity
(3) During the fall, the speed of the source continuously increases under the effect of gravitational attraction and therefore the frequency heard by the person on the platform becomes progressively greater (higher)
Explanation:
A light bulb has a power output of 80 W and it has been left on for 90 seconds. How much work was done?
7200 joules of heat and light energy was dissipated into the air. But no work was done ... no force moved through no distance.
Which of the following actions will decrease the gravitational force between two objects?
Increasing the mass of the objects
Increasing the density of the objects
Increasing the distance between the objects
Increasing the temperature of the objects
Increasing the distance between the objects
here's the Answer :
=》Increasing the distance between the objects.
since, gravitational force is inversely proportional to the distance between the objects, so if the distance increases the force will decrease.
[tex]gravitational \: force \: \: \dfrac{1}{ \alpha } \: \: distance[/tex]
What could be the average human density? Justify?
Answer:
985 kg/m3
Explanation:
The average density of the human body is 985 kg/m3 k g / m 3 , and the typical density of seawater is about 1020 kg/m3 k g / m 3 .
Explanation:
the worldwide human population density is around 7,500,000,000 ÷ 510,000,000 = 14.7 per km2 (38 per sq. mi.). If only the Earth's land area of 150,000,000 km2 (58,000,000 sq. mi.) is taken into account, then human population density is 50 per km2 (129 per sq.
In which of the following situations is there acceleration? (There may be more than one correct answer)
a. A car is sitting at a stoplight. The light turns green and the car begins moving.
b. A car maintains a speed of 10 mi/hr as it turns a corner.
c. When a truck approaches a stop light, it begins to slow down.
d. A car travels at 65 mi/hr.
Which of the following statements is true with
regards to Blackbody radiation?
a)
b)
c)
A blackbody emits more energy at longer
wavelengths as it heats up
A blackbody emits energy at all wavelengths
The shape of the blackbody spectrum
depends on what the source is made of
All of the above
None of the above
00)
e)
2. When braking and turning, you use ___?
a. All four wheels of traction
b. Only the outside edge of your tires
c. Split traction
d. Additional traction
Answer:
split traction
Explanation:
Please help choose one
A B C or D
???
Volleyball took some of its characteristics from handball and tennis
True
False
Answer:
True Because if we observe carefully we will see that some moves of volleyball are similar to handball and tennis
Covalent compounds......
Covalent compounds are characterized by bonding that involves sharing electrons.
Covalent compounds have the ability to share electrons as they mostly have 4 valence electrons.
What are covalent compounds?
Covalent compounds are defined as type of compounds which are formed by the mutual sharing of electrons to form electron pairs between the two atoms.These electron pairs are called as bonding pairs or shared pair of electrons.
Due to the sharing of valence electrons , the atoms are able to achieve a stable electronic configuration . Covalent compounds have bonding which involves many types of interactions like σ bonding,π bonding ,metal-to-metal bonding ,etc.
Sigma bonds are the strongest covalent bonds while the pi bonds are weaker covalent bonds .Covalent bonds are affected by electronegativities of the atoms present in the molecules.Compounds having covalent bonds have lower melting points as compared to those with ionic bonds.
Learn more about covalent compounds,here:
https://brainly.com/question/21505413
#SPJ2
The energy transferred to the water in 100 seconds was 155 000 J. specific heat capacity of water = 4200 J/kg °C
Determine the mass of water in the kettle.
Use Figure 10.
Give your answer to 2 significant figures.
Any help would be appreciated
Answer:
0.37 kg
Explanation:
I'm not a professor myself, but this is how I worked it out:
using the graph, after 100 seconds, the temperature is 100 degrees Celsius.
If we now substitute everything into the specific heat capacity equation, making the mass "m", we would come up with:
4200 = 155000/(m x 100)
If we rearrange and solve for m, we get 0.37 kg.
I'm not sure if I have done this correctly, feel free to correct me.
Hope this helps!
By using the specific heat capacity formula, the mass of water in the kettle is 0.47 kg
Give that the energy transferred to the water in 100 seconds was 155 000 J and the specific heat capacity of water = 4200 J/kg °C
From the graph;
The initial temperature of the water at time zero is 22 degree Celsius
The final temperature of the water at time 100s is 100 degree Celsius
Change in temperature (T) = 100 - 22 = 78 degree Celsius
To determine the mass of water in the kettle, use the heat energy formula below
E = mcT
Substitute all the parameters into the equation
155000 = 4200 x 78 M
Make M the subject of the formula
M = 155000/327600
M = 0.47 kg
Therefore, the mass of water in the kettle is 0.47 kg
Learn more here: https://brainly.com/question/15475909
Please solve this worksheet for me It’s very important please don’t write unnecessary things or else I’ll report please help me i request
Answer:
1. 231.25 mL
2. 218.75 kPa
3. 6.21 L
4. 427.5 mL
5. 83.01 mL
6. 307.6 mL
7. 1.15 L
Explanation:
Boyle's law equation is used in this questions as follows;
P1V1 = P2V2
Where;
P1 = initial pressure
P2 = final pressure
V1 = initial volume
V2 = final volume
Please find the solutions to each subquestion as an attachment
https://forms.office.com/Pages/ResponsePage.aspx?..
Print Management S Show My Homework
worites
10
Calculate the power in resistor X when the voltage across X is 2.1 V and the current in resistor
X is 0.041 A
(2 Points)
Answer:
P = 0.0861 W = 86.1 mW
Explanation:
The electrical power in a resistor is defined as the product of the current passing through that resistor and the voltage across that resistor. Therefore, the formula can be written as follows:
[tex]P = VI[/tex]
where,
P = Power in Resistor X = ?
V = Voltage across resistor X = 2.1 V
I = Current passing through resistor X = 0.041 A
Therefore,
[tex]P = (2.1\ V)(0.041\ A)[/tex]
P = 0.0861 W = 86.1 mW
The mass of an object is 84 kg. Find its weight on the Earth and the Moon.
Answer:
We would take the mass given, 80 kg, and multiply it times the acceleration of Earth's downward pull on that mass, 9.8 m/s/s. So the weight on Earth is 784 newtons. So the weight of the same 80 kg mass on the moon is 133.28 N.
hi
mass is express in Newtons.
On Earth gravity is 9.807 so wieght would be : 9.807 * 84= 823.79
On the Moon garvity is 1.62 so weight would be : 84 *1.62 = 136.08
6. A plane took 3.55 hours to complete its flight. If the distance of the flight was 2840 kilometers, at what average speed did the plane travel? Include the correct unit for full credit.
Answer:
The average speed is 10,082
Explanation:
Do the formula
Distance * time = speed
2840 * 3.55
= 10,082
An 80 kg runner has 3,000 J of kinetic energy. What is her velocity in m/s?
Answer: 8.6m/s
Explanation:From KE=1/2mv^2
In order to make v the subject of the formula we divide both sides by 1/2m. Thus V^2 will be left alone on the RHS. But we are looking for v and not v^2. Thus we find the square root of KE1/2m
Meaning V= sqrt[3000÷1/2 of 80]
=sqrt[3000÷40]
=sqrt(75)
=8.6m/s
Can some one please help me
Answer:
its "up, then down, then up"
Explanation:
Which law best describes contact force
A.
second law
B.
third law
C.
law of gravity
D.
first law
Answer:
b is the answer the third law
Explanation:
B because Newton's second law, which states that the force F acting on a body is equal to the mass m of the body multiplied by the acceleration a of its centre of mass, F = ma, is the basic equation of motion in classical mechanics.
1.) Cameron loads a wheelbarrow full of dirt. She then holds up both handles and begins to push it across her yard. The push Cameron uses to move the wheelbarrow is an example of
trajectory
motion
dynamics
force
2.) Jeremy is pushing his two children on a set of swings. He gives his daughter a push and she swings about three feet high. Jeremy gives his son the same push, but he only swings about two feet high. What could account for the difference in how high the kids got?
Jeremy's daughter has more mass, so it takes less force to get her into the air.
Jeremy's son has more mass, so it would take more force to reach the same height as his daughter.
Jeremy's son has less mass, so it would take more force to reach the same height as his daughter.
Jeremy's daughter has more mass, so she accelerates faster than his son.
Answer:
C (Force)
Explanation:
Cmon we should all know dis
Answer:
force and Jeremy's son has more mass
Explanation:
pushing requires force and the son moves less
list of places in our bodies where HIV is present
Answer: The brain
Explanation:
The brain is an ideal reservoir for our bodies. That is the main one.
Do you think using a homework machine could be considered cheating? Why or why not?
The weight of a cuboid box is 288 N. Find its mass.
Answer:
29.39 kg
Explanation:
From the question,
W = mg...................... Equation 1
Where W = weight of the cuboid box, m = mass of the cuboid box, g = acceleration due to gravity.
make m the subject of the equation
m = W/g.................. Equation 2
Given: W = 288 N
Constant: g = 9.8 m/s²
Substitute these values into equation 2
m = 288/9.8
m = 29.39 kg
Helppppppl!!!!!!!!!!!
Answer:
I think deposition of C is the oldest deposit
Car accelerates uniformly from 22.5 m/s to 46.1 m/s in 2.47
seconds. Determine the acceleration of a car.
Would the following reaction be endothermic or exothermic? Why?
CH4 + 02 --> CO2 + H2O + Energy
A. Exothermic because energy is a reactant
B. Endothermic because energy is a reactant
C. Endothermic because energy is a product
D. Exothermic because energy is a product
Answer:
Exothermic because energy is a product
Explanation:
Since energy is a product, heat was released, meaning that the reaction is exothermic.
Please solve this worksheet for me It’s very important please don’t write unnecessary things or else I’ll report please help me i request
Answer:
1. 231.25 mL
2. 218.75 kPa
3. 6.21 L
4. 427.5 mL
5. 83.01 mL
6. 307.6 mL
7. 1.15 L
8. 440.4 mL
Explanation:
This questions describes Boyle's law. Using Boyle's law equation to solve the questions as follows:
P1V1 = P2V2
Where;
P1 = initial pressure
P2 = final pressure
V1 = initial volume
V2 = final volume
Please find the answers to each question as an attachment.
Help plz for 25 points !! I only have an hour left !
what is the difference between storm spotter and storm chaser?
Answer:
this is just a guess
Explanation:
a storm spotter only spots the storm and a storm chaser looks for the storm????
Would the following reaction be endothermic or exothermic? Why?
CH4 + 02 --> CO2 + H2O + Energy
A. Exothermic because energy is a reactant
B. Endothermic because energy is a reactant
C. Endothermic because energy is a product
D. Exothermic because energy is a product
Answer:
D. Exothermic because energy is a product
Explanation:
ENDOTHERMIC REACTION: A chemical reaction is considered endothermic if the energy is absorbed during the reaction. In other words, if the energy is required by the reactants to proceed with the reaction, then the reaction is endothermic.
EXOTHERMIC REACTION: A chemical reaction is considered exothermic if the energy is released during the reaction. In other words, if the energy is produced as a product of the reaction, then the reaction is exothermic.
Hence, the correct answer for this question will be:
D. Exothermic because energy is a product