Hi there!
Because of Newton's Third Law, the force exerted by the sprinter on the track is equal and opposite to the force exerted by the track on the sprinter.
We can begin by calculating the sprinter's acceleration. Use the equation:
vf² = vi² + 2ad
Rearrange for acceleration:
(vf² - vi²)/2d = a
Plug in values:
(8² - 2²)/2(2.5) = 60/5 = 12 m/s²
Calculate the force:
∑F = ma
∑F = 60 × 12 = 720 N. This is the amount of force exerted by the track on the sprinter in causing him to accelerate forward.
Thus, the backward force exerted by the sprinter on the track is the opposite, or -720 N.
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
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You kick a ball. You are doing work on the ball when...
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:
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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.
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
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.
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
A spiral staircase winds up to the top of a tower in an old castle. To measure the height of the tower, a rope is attached to the top of the tower and hung down the center of the staircase. However, nothing is available with which to measure the length of the rope. Therefore, at the bottom of the rope a small object is attached so as to form a simple pendulum that just clears the floor. The period of the pendulum is measured to be 8.5 s. What is the height of the tower
Answer:
L = 17.94 m
Explanation:
The angular velocity of a simple pendulum is
w = [tex]\sqrt{ \frac{g}{L} }[/tex]
the angular velocity is related to the period
w = 2π / T
we substitute
[tex]\frac{4\pi ^2 }{T^2} = \frac{g}{L}[/tex]
L = [tex]\frac{g T^2}{4 \pi ^2}[/tex]
let's calculate
L = 9.8 8.5² / 4π²
L = 17.94 m
a current of 3 amps flows through a lamp which is connected to a 24 volt battery calculate the lamps resistance
Answer:
8
Explanation:
V = voltage
I = current
R = resistance
V = IR is the equation to find out the Voltage of an item so if we move around the equation so we are trying to resistance it would become R = V/I. So....
V = IR
R = V/I
R = 24/3
R = 8
The national government would like to start a program that would give states money for flood relief. Which of the following states could most likely benefit from a program like this?
Answer:
When a disaster is declared, the Federal government, led by the Federal Emergency Management Agency (FEMA), responds at the request of, and in support of, States, Tribes, Territories, and Insular Areas and local jurisdictions impacted by a disaster.
Explanation:
Water heating over a stove
ahh yes
Y. E. S. W A. T. E. R. A. N. D. S T. ON. V. E
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.
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.
How did Shi Huangdi link the new lands of his empire
Answer:
Many things, such as building the Great Wall of China, and building highways.
Explanation:
What is one benefit of a cardio kickboxing workout?
A. It is a total body exercise.
B. It focuses specifically on aerobics.
C. It focuses specifically on anaerobics.
D. It focuses on the core muscles.
Answer:
D. It focuses on the core muscles
Answer:
A. It is a total body exercise
Explanation:
In cardio kickboxing as described by my school is "
a total body exercise that combines aerobic and anaerobic workoutsan improvement in body fat compositionan efficient use of workout timea boost in confidence and self-esteemrelief of stress and increased energy levelsvaluable self-defense skillsThe first benefit is the one which we are focusing on because all the other answers are correct but A. Total body exercise is the best answer because it covers all of them as an compendious answer
Also I took the test and got this correct
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:
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)
Do you think using a homework machine could be considered cheating? Why or why not?
Pls help! Will mark brainliest!!
Answer:
I would say all of the above
Explanation:
I think this bcuz it says it should be useful and comfortable and so four is correct bcuz they need to know if it feels good and also if it possibly would give a rash or worse. Next, all the other ones would prove how well the suits work in the conditions need for use.
Hope this helps.
Some people say you can get HIV from insect bites. True or false? Why?
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
Electrical potential is measured in units called what
Answer:
Electrical potential is measured in units called volts.
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
Which ray diagram shows reflection
Answer:B
Explanation:
Answer:
The answer is B.
Explanation:
edge2020
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
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
Car accelerates uniformly from 22.5 m/s to 46.1 m/s in 2.47
seconds. Determine the acceleration of a car.
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]
Please help choose one
A B C or D
???
Which of the following decreases the dissolving rate of a solid in water?
A.
crushing the solid
B.
raising the temperature
C.
using larger pieces of solid
D.
stirring constantly
Answer:
Answer is C
Explanation:
Using larger pieces of the solid creates more area for dissolving therefore causing the decrease in dissolving...
Hope this helps