Answer:
3/2 R
Explanation:
Let the Mass of man be m, Mass of earth be M.
By Newtons, law of gravitation,
F = GMm/R^2, Where G is gravitational constant
90 = GMm/R^2
When man weighs 40N,
GMm/(New R)^2 = 40
= 4/9 (90)
GMm/(New R)^2 = 4/9 (GMm/R^2)
(New R)^2 = 9/4 R^2
New R = 3/2 R
Therefore, height is 3/2 R
a car starts from rest and drives at 45 m/s in 20 s. how far did it travel
Answer:
distance=speed×time.
45×20=900m.
What happens when sulfur reacts with potassium?
Which statement describes an advantage of models? Models can be used to communicate and test designs ideas. Models always show the exact size of a system. Models have the ability to develop into complex systems. Models are useful for developing scientific methods.
Answer:
Models are useful for developing scientific methods.
Explanation:
Which statement describes an advantage of models? And Developing is an advantage of a model.
Developing scientific methods.
What are scientific methods?
"The scientific method is a process for experimentation that is used to explore observations and answer questions."
The scientific method has five basic steps, plus one feedback step:
Make an observation.Ask a question.Form a hypothesis, or testable explanation.Make a prediction based on the hypothesis.Test the prediction.Iterate: use the results to make new hypotheses or predictions.
Know more about models here
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write down formula of power
Answer:
Power is a measure of the amount of work that can be done in a given amount of time. So, the formula is the energy or work divided by time:
P = W ÷ T, where p is power , w is work and t is time.
a current of 5 ampere is passed for 2 hours in an electric iron having a resistance of 100 ohms calculate the heat produced
Answer:
[tex] \boxed{\sf Heat \ produced \ (H) = 5 \ kWh} [/tex]
Given:
Resistance (R) = 100 Ω
Current (I) = 5 A
Time (t) = 2 hours
To Find:
Heat developed (H) in the electric iron
Explanation:
Formula:
[tex] \boxed{ \bold{ \sf H = I^2Rt}}[/tex]
Substituting values of I, R & t in the equation:
[tex] \sf \implies H = {5}^{2} \times 100 \times 2 \\ \\ \sf \implies H = 25 \times 100 \times 2 \\ \\ \sf \implies H = 5000 \\ \\ \sf \implies H = 5 \: kWh [/tex]
[tex] \therefore[/tex]
Heat developed (H) in the electric iron = 15 kWh
How many significant figures does the value 0.080 have?
A race car speeds up with an acceleration of 10 m/s2 for 21 s. If its final velocity is 210 m/s, find its initial velocity.
Answer:
answer is 0m/ sec
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A 20 kg block rests on a rough horizontal table. A rope is attatched to the block and is pulled with a force of 80 N to the left. As a result, the block accelerates at 2.5 m/s^2 . The coefficient is Kinetic force friction between the block and the table is ____( Round to the nearest hundredth )
Given :
Mass of block , M = 20 kg .
Force applied , F = 80 N .
Acceleration of block , [tex]a=2.5\ m/s^2[/tex] .
To Find :
The coefficient is Kinetic force friction between the block and the table .
Solution :
We know , Force equation on block is given by :
[tex]F_{net }=F-\mu_k mg \\\\ma = F-\mu_k mg \\\\20\times 2.5 = 80 -\mu_k \times 20 \times 10\\\\\mu_k\times 200=30\\\\\mu_k=\dfrac{30}{200}\\\\\ mu_k=0.15[/tex]
Therefore , coefficient is Kinetic force friction between the block and the table is 0.15 .
Hence , this is the required solution .
A roadrunner at rest suddenly spots a rattlesnake slithering directly away at a constant speed of 0.75 m/s. At the moment the snake is 10. Meters from the bird, the roadrunner starts chasing it with a constant acceleration of 1.0 m/s^2. How long will it take the roadrunner to catch up to the snake?
Answer:
The roadrunner will take approximately 5.285 seconds to catch up to the rattlesnake.
Explanation:
From the statement we notice that:
1) Rattlesnake moves a constant speed ([tex]v_{S} = 0.75\,\frac{m}{s}[/tex]), whereas the roadrunner accelerates uniformly from rest. ([tex]v_{o, R} = 0\,\frac{m}{s}[/tex], [tex]a = 1\,\frac{m}{s^{2}}[/tex])
2) Initial distance between the roadrunner and rattlesnake is 10 meters. ([tex]x_{o, R} = 0\,m[/tex], [tex]x_{o,S} = 10\,m[/tex])
3) The roadrunner catches up to the snake at the end. ([tex]x_{S} = x_{R}[/tex])
Now we construct kinematic expression for each animal:
Rattlesnake
[tex]x_{S} = x_{o,S}+v_{S}\cdot t[/tex]
Where:
[tex]x_{o, S}[/tex] - Initial position of the rattlesnake, measured in meters.
[tex]x_{S}[/tex] - Final position of the rattlesnake, measured in meters.
[tex]v_{S}[/tex] - Speed of the rattlesnake, measured in meters per second.
[tex]t[/tex] - Time, measured in seconds.
Roadrunner
[tex]x_{R} = x_{o,R} +v_{o,R}\cdot t +\frac{1}{2}\cdot a\cdot t^{2}[/tex]
Where:
[tex]x_{o, R}[/tex] - Initial position of the roadrunner, measured in meters.
[tex]x_{R}[/tex] - Final position of the roadrunner, measured in meters.
[tex]v_{o,R}[/tex] - Initial speed of the roadrunner, measured in meters per second.
[tex]a[/tex] - Acceleration of the roadrunner, measured in meters per square second.
[tex]t[/tex] - Time, measured in seconds.
By eliminating the final positions of both creatures, we get the resulting quadratic function:
[tex]x_{o,S}+v_{S}\cdot t = x_{o,R}+v_{o,R}\cdot t +\frac{1}{2}\cdot a \cdot t^{2}[/tex]
[tex]\frac{1}{2}\cdot a \cdot t^{2} + (v_{o,R}-v_{S})\cdot t + (x_{o,R}-x_{o,S}) = 0[/tex]
If we know that [tex]a = 1\,\frac{m}{s^{2}}[/tex], [tex]v_{o, R} = 0\,\frac{m}{s}[/tex], [tex]v_{S} = 0.75\,\frac{m}{s}[/tex], [tex]x_{o, R} = 0\,m[/tex] and [tex]x_{o,S} = 10\,m[/tex], the resulting expression is:
[tex]0.5\cdot t^{2}-0.75\cdot t -10=0[/tex]
We can find its root via Quadratic Formula:
[tex]t_{1,2} = \frac{-(-0.75)\pm \sqrt{(-0.75)^{2}-4\cdot (0.5)\cdot (-10)}}{2\cdot (0.5)}[/tex]
[tex]t_{1,2} = \frac{3}{4}\pm \frac{\sqrt{329}}{4}[/tex]
Roots are [tex]t_{1} \approx 5.285\,s[/tex] and [tex]t_{2}\approx -3.785\,s[/tex], respectively. Both are valid mathematically, but only the first one is valid physically. Hence, the roadrunner will take approximately 5.285 seconds to catch up to the rattlesnake.
What is the difference between centrifugal force and centripetal force???
Answer:
Centripetal force is the force that is necessary to keep an object moving in a curved path and that is directed inward toward the center of rotation, while centrifugal force is the apparent force that is felt by an object moving in a curved path that acts outwardly away from the center of rotation
Explanation:
Hope this helps!
Brainliest if correct pls
What do you like about science?
Answer:
nngh have
bjruh hjrhhj be rnrnnrnrnnnrnjrjnnnnnnnnrnrn n n and I was nrn
Explanation:
jbbbbbhhhjjnnnnnnnnnnjhvcc
Explanation:
help pls!!
acceleration:
a) the rate of change of position
b) acceleration caused by the force of gravitation
c) the rate of change in velocity; speeding up, slowing down, or changing direction
d) for every action force, there is an equal and opposite reaction force
Answer:C.
Explanation:
The rate of change in velocity; speeding up, slowing down, or changing direction
This means divide or to take apart the pieces. ( science )
Answer:
disassemble, break apart,divide, separate
Explanation:
just know and have learned it....
If you have 2 flowers, but then your friend gives you one, how many do you have?
Answer:
3
Explanation:
Answer:
2+1=3
Explanation:
cause why not
what are fossil fuels?
Answer:
Fossil Fuels are natural fuels like coal or gas that were formed millions of years ago and take millions of years to form. They are formed from the remains of past living organisms.
Explanation:
Well you do no really need an explanation for this one...
Plz help me this question is hard to under stand
Answer:
____________
in real world conditions?
it seems the most plausible.
Answer (B)
Cars are tested on closed tracks and race tracks so rule out A, D. Tha leaves us with B, C. C is kind of a real-world situation so the answer is most likely, B.
Which of the following is an example of an electromagnetic wave? (2 points)
Red light
Ocean waves
Sound waves
Earthquakes
Answer:
a
Explanation:
True or false: We still use the republican calendar created by the French.
2. What is the difference between distance and displacement?
Answer:
Distance is a scalar quantity that refers to "how much ground an object has covered" during its motion. Displacement is a vector quantity that refers to "how far out of place an object is"; it is the object's overall change in position.
Explanation:
:)
Answer: The complete length of the path between any two points is called distance. Displacement is the direct length between any two points when measured along the minimum path between them.
Explanation: It's what's!!
Find the average velocity (in m/s) of a bicycler that starts 200 meters north of Norwalk and is 2,000 meters north after 45 minutes.
Answer:
The answer is 10
Explanation:20 x 10 = 200
5. What is the velocity of a Nolan Catholic football player if he runs 200.0 m in 24.0 s?
Answer:
[tex] \boxed{ \bold{ \huge{ \boxed {\sf{8.33 \: m \:/s \: }}}}} [/tex]
Explanation:
Distance travelled = 200 metre
Time taken = 24 second
Velocity = ?
Finding the velocity
[tex] \boxed{ \sf{velocity = \frac{distance \: travelled \: }{time \: taken}}} [/tex]
[tex] \dashrightarrow{ \sf{velocity = \frac{200 \: m}{24 \: s} }}[/tex]
[tex] \dashrightarrow{ \sf{velocity = 8.33 \: m/s}}[/tex]
Hope I helped!
Best regards!
I want to know if high school starts hard and gets easier as the year goes? in your opinion
Answer:
It depends on how much you stress I recommend starting calm!
Explanation:
Answer:
I'm a senior right now, but I think the subjects gradually get more difficult, it's not all too difficult though, it's just stressful because the amount of work your expected to finish.
Explanation:
a cross country runner runs 10 km in 40 minutes. what is his average speed
◈ Average speed is measured as the ratio of total distance travelled to the total time taken.
Given : d = 10km and t = 40min
To Find : Vav
_________________________________
፨ Conversion :-
60 min = 1 h
40 min = 40/60 = 2/3 h
[tex]:\implies\sf\:V_{av}=\dfrac{d}{t}[/tex]
[tex]:\implies\sf\:V_{av}=\dfrac{10\times 3}{2}[/tex]
[tex]:\implies\sf\:V_{av}=\dfrac{30}{2}[/tex]
[tex]:\implies\:\boxed{\bf{\orange{V_{av}\:15\:kmph}}}[/tex]
which type of mixture is air explain
Answer:Three elements make up over 99.9 percent of the composition of dry air: these are nitrogen, oxygen, and argon.
Explanation:
Answer: Air is an gaseous substance
Explanation:
Air is a homogeneous mixture of the gaseous substances nitrogen, oxygen, and smaller amounts of other substances. Salt, sugar, and many other substances dissolve in water to form homogeneous mixtures.
Identify the term used to describe the number of protons and neutrons that are present in an atomic
nucleus.
A sled is at rest at the top of a slope 2 m high. The sled has a mass of 45 kg. What is the sled’s potential energy?
Answer:
its 882 J
Explanation:
the answer is D for edge
In a college of exactly 2560 students, exactly 50 % are male. What is the number of female students?
When writing a number in scientific notation, how many digits should be to
the left of the decimal point?
o
A. None
B. One
C. Two
D. It depends on how precise you want your answer to be.
Answer:
C
Explanation:
Which of the following is an example of a chemical property? Density Solubility Flammability Magnetism
Answer:
Hey there!
Flammability is a chemical property. It doesn't change based on what state of matter the object is in.
Let me know if this helps :)
Answer:Flamibilliety
Explanation:
A person driving a car suddenly applies the brakes. The car takes 7.0 s to come to rest while traveling 26 m at constant acceleration. What was the initial speed of the car (in m/s)?
Answer:
7.43 m/s
Explanation:
Time taken for car to stop = 7.0 s
distance traveled before coming to rest = 26 m
Final speed of the car = 0 m/s (since it stops)
initial speed of the car = ?
To get the final speed, we use the equation
s = [tex]\frac{1}{2}t(u + v)[/tex]
where
s is the distance traveled before stopping
u is the initial speed = ?
v is the final speed = 0 m/s
t is the time = 7 s
substituting values, we have
26 = [tex]\frac{1}{2}*7*(u + 0)[/tex]
26 = 3.5u
u = 26/3.5 = 7.43 m/s