A car is moving at a speed of 72 km / h on a horizontal section. What is the braking distance of the car if the friction force is equal to the size of the weight of the car? (20 m) (+ formula)
Answer:
20.4m
Explanation:
72kmhr(1000mkm)(hr3600sec)=20ms
Use principles of conservation of energy.
The initial kinetic energy of the car is equal to the work done by friction during braking:
KE=Wfric
12mv2=(Ffric)d
but the force of friction = weight of the car = mg
12mv2=mgd
mass cancels in both terms, which tells us the answer is independent of mass
12v2=gd
12202=(9.81)d
d=20.4m
Note that the correct answer should actually be 20. m with only 2 significant figure accuracy since 72 km/hr only has 2 sig fig accuracy.
How do you solve problems involving acceleration
Answer:
Velocity/time =acceleration
Acceleration x time = velocity
Velocity/acceleration=time
The tail of a comet always points Select one: a. in the direction of the comet's motion. b. away from the Sun and becomes longest and brightest at perihelion. c. toward the Sun and disappears at perihelion. d. away from the Sun and disappears at perihelion. e. toward Earth and never varies.
the source of a magnetic field is a moving _________.
Answer:
electron
Explanation:
The source of a magnetic field is a moving _________.
\/
The source of a magnetic field is a moving electron.
The spinning of the electrons around the nucleus of an atom creates a magnetic field.
Have a nice day!
I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)
- Heather
plz help, dont need to do the last question
Answer:
Explanation:
I dont understand what its saying .....?
As the skydiver's ______increases, so does the magnitude of the force due to friction.
Answer:
speed?
Explanation:
give me more information
Three of the forces in nature attract particles together, with varying strengths, to build the universe. Which is the only one that energizes the universe by making nuclear fusion possible
Answer:
The photon or quantum of light
Explanation:
whaT HAPPENS WHEN a net force act's
on a moving object
Which explains why scientists often prefer to measure mass rather than weight?
It is always the same.
It is affected by gravity.
Answer:
scientists often prefer to measure mass rather than weight because weight is affected by gravity while mass is not. Mass is always the same.
Explanation:
Weight is a force rather than a measure of the amount of matter something contains. The same amount of matter can have different weights depending on where it is. Mass directly measures the amount of matter present and remains the same no matter where it's measured.
As the temperature of an air mass increases, its atmospheric pressure______. Group of answer choices
Answer:
its atmospheric pressure decreases
When the temperature of an air mass increases, its atmospheric pressure drops
ok done. Thank to me :>
Newton’s First Law of Motion applies to
1) objects at rest
2) objects in motion
3) both moving and non moving objects
4) objects that are accelerating
Answer:
3) both moving and non moving objects
Hope it helps:)
Trên một sợi dây đàn hồi dài 1,2 m hai đầu cố định đang có sóng dừng Biết sóng truyền trên dây có tần số 100 Hz và tốc độ 60 m trên giây số nút sóng trên dây là
Answer:english please
Explanation:
a person walks 9 meters to the right and 8 meters to the left what's the distance and displacement
Answer:
walked: 17 meters
displacement: 1
Explanation:
so you add 9+8 and the displacement is 1 b/c when you moved back those 8 meters you were still 1 meter away from where you where originally standing
What are some simple machines that decrease mechanical advantage used to do? increase work decrease work multiply distance to increase speed.
Answer:
Wheel and axleForce multipliersLeverInclined planePulleyScrewWedgeExplanation:
Simple machines are devices with no, or very few, moving parts that make work easier. Many of today's complex tools are just combinations or more complicated forms of the six simple machines, according to the University of Colorado at Boulder. For instance, we might attach a long handle to a shaft to make a windlass, or use a block and tackle to pull a load up a ramp. While these machines may seem simple, they continue to provide us with the means to do many things that we could never do without them.
Have a great day! :D
Some machines decrease mechanical advantage and are utilized to multiply distance to decrease speed.
What is the mechanical advantage?Mechanical advantage can be described as a measure of the ratio of output force to input force in a system. Mechanical advantage is used to analyze the forces in simple machines such as levers and pulleys.
Mechanical Advantage= output force (load) /input force(effort)
The mechanical advantage will increase as the slope of the inclined plane decreases but the load has to move with more distance. Under the mechanical advantage, the distance the load will move will be a fraction of the distance through applied force.
Thus, the mechanical advantage is decreased by some simple Machines decrease and are used to multiply distance to decrease speed.
Learn more about Mechanical advantages, here:
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What do these two changes have in common
a slice of banana turning brown
bleaching clothes
Answer:
They get air inside
Explanation:
bananas turn brown when air is inside
If professor X can move things with his mind.Then why cant he move his legs?
Answer: Varies
Explanation:
Because moving his legs require force.
Answer:
He is also a low-level telekinetic
Explanation:
He is a telepath and doesn’t have telekinesis btw.
Nbel! You’re okay! What happened to you?
Answer:
Wanna be frie nds?
Explanation:
Im smort big brain
Answer:
hello wanna be fr iends and cha-t?
Explanation:
A student wants to show the transfer of heat energy without matter. Which investigation design would best help the student
Answer:
C
Explanation:
Answer:
C) an investigation of conduction through collisions between particles in space
what is the medium for the sound waves for whales to communicate with each other?
Answer:
SONGS CLICKS AND WHISTLE
Explanation:
The surface of this planet is obscured by an atmosphere of thick clouds and toxic gases. What planetary body is it
Answer:
Venus....
Explanation:No explanation just simple answers
Which of the following explains why NASA mandated that space food could NOT crumble or come apart?
Crumbs may cause electronics to malfunction.
There is no way to clean crumbs, so all food must be contained.
Floating crumbs may get into astronauts’ eyes.
Crumbs increase the risk of bacteria development.
Answer:
C.
Floating crumbs may get into astronauts’ eyes.
A crankshaft of an engine increases its spin from 1,000 rpm to 1,500 rpm in 0.5 s. What is its angular acceleration? (1 rev=2π rad)
600 rad/s2
100 rad/s2
500 rad/s2
60 rad/s2
the answer is 100 rad/s2
What is the equation to calculate speed?
Answer:
the equation :-
speed = distance ÷ time
Science Questions :)
Answer:
The box will move diagonally down to the right
Do distance and Gravity have a _____ relationship?
Answer:
proportional...?
Explanation:
not sure if thats correct...
hope this helped tho
try your best!
mark me brianliest :D
is climbing stairs work done
Answer:
The work you did in climbing the stairs is the force you applied (your weight) times the distance you moved upward (the height of the stairs.) So yes, climbing stairs is work done.
Explanation:
Hope this helped, nya~ :3
A flea sits on the edge of a classic record album that is making 1 revolution in 0.56s. The flea is 0.20m from the center of the record
a. what is the fleas velocity?
b. What is the fleas centripetal acceleration?
Hi there!
We can begin by finding the angular velocity using dimensional analysis:
[tex]\frac{1 rev}{0.56 s} * \frac{2\pi rad}{1 rev} = 11.22 rad/sec[/tex]
(A)
Find the flea's velocity using the following relationship:
v = ωr
v = (11.22)(0.20) = 2.24 m/s
(B)
Centripetal acceleration is given by:
a = ω²r
a = (11.22²)(0.20) = 25.18 m/s²
A runner slows down after completing a race. Her deceleration is 0.25 m/s2. After 5 s she is travelling at 4 m/s, determine her initial velocity.
Please find attached photograph for your answer.
Hope it helps.
Do comment if you have any query.
The initial velocity of the runner is 5.25 m/s.
What is deceleration?
You've probably seen that when there's a lot of traffic and there are more bikes blocking us, we tend to slow down the speed of our bikes.
Therefore, deceleration is defined as a reduction in speed as the body moves away from the beginning location. The opposite of acceleration is deceleration.
Given parameters:
Deceleration of the runner: a = 0.25 m/s².
Time interval: t = 5 second.
Final velocity: v = 4 m/s.
We have to find initial velocity of the runner: u = ?
From definition of deceleration, it can be written that:
deceleration = (initial velocity - final velocity) time interval
0.25 = (u -4)/5
u = 5.25 m/s.
Hence, initial velocity of the runner is 5.25 m/s.
Learn more about deceleration here:
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A box of mass 6.0 kg is accelerated from rest
across a floor at a rate of 6.0 m/s² for 9.0 s.
Find the network done on the box
[tex]\text{Given that },\\\text{Mass, m = 6 kg}\\\\\text{Acceleration, a = 6 } \text{m} \text{s}^{-2}\\\\\text{Time, t=9 sec}\\\\\text{Displacement, }s=ut + \dfrac 12 at^2 = \dfrac 12 at^2 = \dfrac 12 \times 6 \times 9^2 = 243 ~m}\\\\\ \text{Work,} ~W = Fs = mas = 6 \times 6 \times 243 = 8748 ~ J}[/tex]
Hi there!
We know that:
[tex]W = \Delta KE = \frac{1}{2}m(\Delta v)^2[/tex]
We can begin by solving for the final velocity using the equation:
[tex]v_f = v_i + at[/tex]
The box starts from rest, so:
[tex]v_f = at\\\\v_f = 6(9) = 54 m/s[/tex]
Now, we can find the kinetic energy:
[tex]KE = \frac{1}{2}mv^2\\\\KE = \frac{1}{2}(6)(54^2) = 8748 J[/tex]
Thus:
[tex]W = \Delta KE\\\boxed{W = 8748 J}[/tex]
Sound is repeated near hills. Give reason
Explanation:
Sound is repeated near hills due to reverberation. The sound effect is prolonged is an empty room because , in a furnished room, reverberation occurs less than in a room with no furniture.
Answer:
sound that occurs in nature, such as those of animal, trees, people, the wind, the rain, etc. are the natural sounds. it is heard near the hill because of the echo and the reverberation of the sound