Answer:
13.78 m/s
Explanation:
Given that:
The mass of the girl & her bicycle = 42 kg
The speed at the top of the hilll= 4 m/s
The height of the hill = 14.3 m
The length of the hill (distance) = 112 m
The frictional force = 20 N
To find the speed at the bottom of the hill; we need to carry out the following processes.
The workdone by gravity = mass × acceleration due to gravity × Δh
= 42 × 9.8 × ( 14.3 - 0 )
= 5885.88 joules
The workdone by the friction = Force × distance = - 20 × 112 (since she is riding down the hill)
The workdone by the friction = -2240 Joules
The initial Kinetic friction = 1/2 mv²
= 1/2 × 42 × 4²
= 336 Joules
The final kinetic energy = Initial Kinetic energy + total work
The final kinetic energy = (336 + 5885.88 - 2240) Joules
The final kinetic energy = 3981.88 Joules
Using the final kinetic energy = 1/2 mv²
3981.88 = 1/2 × 42 × v²
3981.88 = 21 v²
v² = 3981.88/21
v² =189.61
v = [tex]\sqrt{189.61}[/tex]
v = 13.78 m/s
Therefore, the speed at the bottom = 13.78 m/s
PLEASE LOL I NEED IT NOW!
Answer:
C
Explanation:
I did this on edge an that was the answer
HELP !!!!!!! I NEED A QUICK ANSWER IM CONFUSED !!!!
Answer:
bouyant force - the upward force on an object in a fluid
boiling point - the temperature at which a liquid becomes a gas
solubility - the ability of a substance to dissolve in another
conductivity- the ability to transfer heat or electricity
density - the amount of mass in a given volume
4 Which statements apply to compressional waves? Choose more than one answer. Similar to ocean waves Cause molecules to vibrate Travel through outer space Travel through air, liquid, or solid Move in the same direction as energy flow Move at right angles to the direction of energy flow
Answer:
* viajan a través del aire, liquido o solido
*Moverse en la misma dirección que el flujo de energía
Explanation:
En el análisis de ondas existen dos tipo fundamentales: Transversales y longitudinales.
La ondas transversales las oscilación de la partícula es perpendicular al movimiento de la misma.
En la onda longitudinal el movimiento de la partícula es en la misma dirección que el movimiento de la onda, por esta razón están ondas se llaman ondas de compresión.
En base a las definiciones iniciales las frases correctas son:
* viajan a través del aire, liquido o solido
*Moverse en la misma dirección que el flujo de energía
Answer:
Cause molecules to vibrate
Travel through air, liquid, or solid
Move in the same direction as energy flow
Explanation:
A sales clerk at a local hardware store sells you a hammer with a mechanical advantage of 10 when used to pry up nails. You are able to create a force of 60 N. Using the hammer, what would be the maximum force that could be generated to remove a nail?
Answer:
W = 600 N
Explanation:
The mechanical advantage of any machine is the ratio of the load or weight to the effort applied. Hence, the general formula for mechanical advantage is as follows:
M.A = W/P
where,
M.A =Mechanical Advantage of Hammer = 10
W = Maximum force that could be generated = ?
P = Force created by me = 60 N
Therefore,
10 = W/60 N
W = 10*60 N
W = 600 N
The average speed of an object which moves 100 m in 5 seconds is?
Answer:
A car
Explanation:
A car can travel 100 m in 5 seconds
Hope this helps!
How many chromosomes does a human diploid cell have
Answer:
23
Explanation:
Which of the following is a growing threat to animals that are believed to be critical to the success of natural remedies?
competition for resources
disease and illness
poaching by hunters
increase in predators
Answer:
I would think the first and the third answer
Answer:
i would say 3rd cause other may slightly effect
a 45.0-N force pushes a cart 15.0 meters down a hallway. What is the work done on the cart?
Answer:
675 NExplanation:
The work done by an object can be found by using the formula
workdone = force × distance
From the question we have
workdone = 45 × 15
We have the final answer as
675 NHope this helps you
A child is sitting on a merry-go-round 2.8 m from the
center. If the tangential velocity of the ride is 0.89 m/s,
what is the centripetal acceleration of the dragonfly?
A. 0.11 m/s2
C. 0.32 m/s2
B. 0.28 m/s2
D. 2.2 m/s2
Answer:
b
Explanation:
a=v2/r
=0.89^2/2.8
=0.2828...
=0.28
The centripetal acceleration of the child sitting on a merry-go-round 2.8 m from the center will be 0.283 m/s².
What is centripetal acceleration?
Centripetal acceleration is the constant change in velocity necessary for an object to maintain a circular path. We can write the formula for centripetal acceleration as -
a[C] = v[T]²/r
where -
v[T] is tangential velocity
r is radius
Given is a child is sitting on a merry-go-round 2.8 m from the center and the tangential velocity of the ride is 0.89 m/s.
We can write -
Radius [r] = 2.8 m
Tangential velocity = v[T] = 0.89 m/s.
Using the formula for centripetal acceleration -
a[C] = v[T]²/r
a[C] = (0.89 x 0.89)/2.8
a[C] = 0.283 m/s²
Therefore, the centripetal acceleration of the child sitting on a merry-go-round 2.8 m from the center will be 0.283 m/s².
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8. List three temperature scales. Then write the boiling and freezing
points of water one each scale.
Explanation:
For most temperature scales, the boiling point of water and the freezing point is used to calibrate it.
Three known temperature scales;
Kelvin scale Celcius scale Fahrenheit scaleKelvin scale Celcius scale Fahrenheit scale
Freezing point 273K 0°C 32°F
Melting point 373K 100°C 212°F
The media often place heavy emphasis on the opinions and actions of celebrities such as actors and sports stars should we pay attention to these opinions and actions choose one side of this argument and write your essay in support of it
Answer:
No, we should not pay attention to these opinions. (Find the essay below)
Explanation:
Celebrities are people who are prominent or well known because of the work that they do. Actors and sports stars are rightly classified as celebrities because their work affords them a lot of exposure. We see them on television, the internet and social media, and hear about their deeds and accomplishments on the radio.
This group of people always have their opinions about life and other topics of interest which they air when interviewed or when they decide to volunteer the information on their own accord. Most times fans who love them value their opinion so much that they even adjust to them or view it as the standard. For these fans, celebrities are their role models. They tend to copy their hairstyles, modes of dressing, and their opinions! Advertisers key to this fact when they use them to promote their goods.
It is very wrong to hold the opinions and actions of celebrities as the gold standard because they are imperfect and are prone to mistakes. Celebrities are just like any other one of us who have opinions or behave in ways that are sometimes wrong. Copying their every move, action, and opinions would be potentially damaging to us. Their opinions should be taken with a pinch of salt.
It is important that while fans maintain the love they have for their favorite celebrities, they also endeavor to have a mind of their own. Each person should know what works for him or her and live by such. It would be a great mistake to be easily carried away by the opinions of others.
Conclusively, balance is key. Love for celebrities should never cloud an individual's thinking. When this is done, future heartaches that come from adhering to wrong opinions can be avoided.
We should not pay attention to the opinions and actions that are portrayed by the media about celebrities.
Celebrity simply means a condition of fame or public recognition of an individual or group due to the attention that's given to them by the media.It should be noted that we should not pay attention to the opinions and actions that are portrayed by the media about celebrities.Sometimes, the media portrays a person in a bad light while others can be portrayed better even if they did something similar. Therefore, one should not pay attention to what the media says about celebritiesRead related link on:
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Which statement accurately describes current electricity?
A. Positively charged particles build up on an object's surface. B. Negatively charged particles build up on an object's surface. C. Positively charged particles move from one point to another. D. Negatively charged particles move from one point to another.
Answer: negatively charged particles move from one point to another
Explanation:
In electricity, negatively charged particles move from one point to another. The correct option is D.
What is electricity?Electric current is what causes electricity to exist and move. We can transmit energy using electricity so that we can carry out easy tasks.
The movement of electrons through conductors like copper wires is its most well-known manifestation. Electrical energy is commonly referred to as "electricity."
The flow of electrical power, commonly referred to as a charge, is the source of the energy type known as electricity.
Our homes, lights, and electrical devices are all powered by electricity. Resources including coal, energy, natural gas, and oil are used to generate power.
Particles that are negatively charged in electricity travel from one location to another.
Thus, the correct option is D.
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A child attempts to move a 90.01 kilogram refrigerator in order to retrieve a rubber
ball from behind it. If she is able to slide the refrigerator across the floor with 55
Newtons of force (ignoring friction), what would be its acceleration?
Answer:
[tex]a=0.611\ m/s^2[/tex]
Explanation:
Given that,
Mass of a refrigerator, m = 90.01 kg
She is able to slide the refrigerator across the floor with 55 N of force.
We need to find the acceleration of the refrigerator.
Let it is a. Using second law of motion:
F = ma
[tex]a=\dfrac{F}{m}\\\\a=\dfrac{55\ N}{90.01\ kg}\\\\a=0.611\ m/s^2[/tex]
So, its acceleration is [tex]0.611\ m/s^2[/tex].
which of the following is a chemical property of a mineral?
A Hardness
B Luster
C Atomic structure
D Color
Hardness, color , and luster.
But since you can pick one, I would say hardness
Which statement best describes the importance of joints in the roadways of Bridges ?
a. Joints strengthen the roadway to support cars and trucks
b. Joints allow the roadway to expand and contract with varying outside temperatures
c. Joints allow the roadway to expand and contract as cars put force on the bridge
d. Joints allow the bridge to be built in smaller, easier to assemble pieces.
Answer:
i think it's a or c hope it helps :)
Explanation:
u don't have to give brainliest tho it's fine save ur points :)
A ball is dropped from rest from the top of a building. What force is responsible for the downward motion of the ball?
the force of gravity
the force of tension
the normal force
the pushing force
please help
Answer: The force of gravity
Mary Jo went on riding her horse through the trails. Her pace was 8 km/hr. She left at 8:30 am and got back to the barn at 9:00 am. How far did she go? Question 4 options: 16 m/s 4 m/s 4 km 16 km
Answer:
4km
Explanation:
Distance=speed x time
Knowing this we know the time and speed
so it is 8 x .5= D
And 8 x .5 =4
If you have any questions let me know
Im just a little confused right now
Answer:
C
YExplanation:
Please help me........
Answer:
.
Explanation:
Answer:
the pelvice
Explanation:
During take-off a 8kg model rocket, initially at rest, burns fuel for 6.3s causing its speed to increase from rest to 60m/s during this time despite experiencing a 50N drag.
What is the magnitude of the net force on the rocket?
What is the strength of the thrust?
What is the magntiude of the rocket's acceleration?
What is the rocket's height at the instant it runs out of fuel?
The rocket attains a speed of 60 m/s in a matter of 6.3 s, so it is undergoing an acceleration a of
a = (60 m/s - 0) / (6.3 s) ≈ 9.52 m/s²
During launch, the only forces acting on the rocket are directed vertically:
• its weight (pointing down) with magnitude W,
• drag (pointing down) with magnitude 50 N, and
• thrust (pointing up) with magnitude T.
(a) By Newton's second law, the magnitude of the net force is proportional to the acceleration according to
∑ F = m a
where m is the mass of the rocket, so the magnitude of the net force is
(8 kg) (9.52 m/s²) ≈ 76.2 N
and it is directed upward.
(b) Expanding the equation from part (a) gives
T - W - 50 N = (8 kg) (9.52 m/s²)
The weight is
W = (8 kg) g = (8 kg) (9.80 m/s²) = 78.4 N
so the thrust force is
T ≈ 76.2 N + 78.4 N + 50 N ≈ 205 N
(c) We found this earlier, a ≈ 9.52 m/s².
(d) The rocket's height y at time t is given by
y = 1/2 a t ²
so that after 6.3 s, it will have reached a height of
y = 1/2 (9.52 m/s²) (6.3 s)² = 189 m
A 25 kg rock falls for 2.7 seconds. How many meters tall was the building?
Answer:
35.7m
Explanation:
Given parameters:
Mass of rock = 25kg
Time of fall = 2.7s
Unknown:
Height of the building = ?
Solution:
To solve this problem, we will use one of the motion equations;
S = ut + [tex]\frac{1}{2}[/tex] gt²
S is the height
u is the initial velocity = 0m/s
t is the time
g is the acceleration due to gravity
S = (0 x 2.7) + [tex]\frac{1}{2}[/tex] x 9.8 x 2.7² = 35.7m
Explain the Conversation of Mass.
Answer:
The law of conservation of mass or principle of mass conservation states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as the system's mass cannot change, so quantity can neither be added nor be removed
Explanation:
Hope this helps!! Please consider marking brainliest! Have a good one!!
it is difficult to catch fast moving crickrt ball than fast moving tennis ball why?
Answer:
because of its mass. Momentum is directly propotional to the mass of a body
Answer:
Mass
Explanation:
A tennis ball has a mass of around 57 grams and a cricket ball has a mass of around 156 grams. It's much easier to catch a fast moving tennis ball because it is lighter than a cricket ball. Hope this helps x
An 85 kg man and his 35 kg daughter are sitting on opposite ends of a 3.00 m see-saw. The see-saw is anchored in the center. If the daughter sits 0.20 m
from the left end, how far from the right end would the father have to sit for the see-saw to be in balance? (g = 10)
type your answer...
Answer:
0.54m
Explanation:
Step one:
given data
length of seesaw= 3m
mass of man m1= 85kg
weight = mg
W1= 85*10= 850N
mass of daughter m2= 35kg
W2= 35*10= 350N
distance from the center= (1.5-0.2)= 1.3m
Step two:
we know that the sum of clockwise moment equals the anticlockwise moment
let the distance the must sit to balance the system be x
taking moment about the center of the system
350*1.3=850*x
455=850x
divide both sides by 850
x=455/850
x=0.54
Hence the man must sit 0.54m from the right to balance the system
what is meant by the term moment in "physics".
what do you mean by pressure
A pendulum is transported from sea-level, where the acceleration due to gravity g = 9.80 m/s2, to the bottom of Death Valley. At this location, the period of the pendulum is decreased by 5.00%
Answer:
[tex]g'=10.78\ m/s^2[/tex]
Explanation:
The time period of a simple pendulum is given by :
[tex]T=2\pi \sqrt{\dfrac{L}{g}}[/tex]
L is length of the pendulum and g is acceleration due to gravity
At the bottom of Death valley, g = 9.8 m/s²
We need to find the value of g if the period of the pendulum is decreased by 5.00%.
T'=(T-0.05T)= 0.95 T
[tex]T\propto \dfrac{1}{\sqrt{g} }\\\\\dfrac{T}{T'}=\sqrt{\dfrac{g'}{g}}\\\\\dfrac{T}{0.95T}=\sqrt{\dfrac{g'}{9.8}}\\\\\dfrac{1}{0.95}=\sqrt{\dfrac{g'}{9.8}}\\\\1.1=\dfrac{g'}{9.8}\\\\g'=10.78\ m/s^2[/tex]
So, the new value of acceleration due to gravity is [tex]10.78\ m/s^2[/tex].
Water at 15°C (rho = 999.1 kg/m³ and μ = 1.138 × 10⁻³ kg/m·s) is flowing steadily in a 29-m-long and 6-cm-diameter horizontal pipe made of stainless steel at a rate of 10 L/s. Determine the pressure drop, the head loss, and the pumping power requirement to overcome this pressure drop. The roughness of stainless steel is 0.002 mm.
Answer:
Explanation:
From the given information:
We can estimate the cross-sectional area of the pipe by using the formula:
[tex]A_c = \dfrac{\pi}{4} D^2[/tex]
[tex]A_c = \dfrac{\pi}{4} (6 \times 10^{-2} \ m)^2[/tex]
[tex]A_c = 0.0028274 \ m^2[/tex]
To find the average velocity of the water flowing through the pipe by using the formula;
[tex]V = \dfrac{\mathtt{V}}{A_c}[/tex]
[tex]V = \dfrac{10 \times 10^{-3} \ m^3/s}{0.0028274}[/tex]
[tex]V = 3.537 \ m/s[/tex]
However, the Reynolds number can be determined by using the equation
[tex]Re= \dfrac{\rho \times V \times D}{\mu}[/tex]
[tex]Re= \dfrac{(999.1 \ kg/m^3) \times (3.537 \ m/s) \times (6 \times 10^{-3} \ m)}{1.138 \times 10^{-3} \ kg/m.s}[/tex]
Re = 18631.7225
From above, Re> 4000, thus, the flow will be turbulent.
By using Colebrook's equation in a turbulent flow; we have the following expression for Colebrook's equation:
[tex]\dfrac{1}{\sqrt{f}}= -2.0 \ log \bigg ( \dfrac{\epsilon/D_h}{3.7}+ \dfrac{2.51}{Re \sqrt{f}} \bigg )[/tex]
where;
[tex]f[/tex] = frictional force = ???
[tex]\epsilon[/tex] = roughness of steel= 0.002 mm
Replacing our values into the above equation, we have:
[tex]\dfrac{1}{\sqrt{f}}= -2.0 \ log \bigg ( \dfrac{ 2\times 10^{-6 \ m }/6 \times 10^{2 }\ m}{3.7}+ \dfrac{2.51}{18631.7225 \sqrt{f}} \bigg )[/tex]
By solving the above equation for f; we get
f = 0.026409
The pressure drop in flow;
[tex]\Delta P_L = f \dfrac{L}{D} \dfrac{\rho V^2}{2}[/tex]
[tex]=0.026409(\dfrac{29}{0.06})(\dfrac{999.1*3.537^2}{2})[/tex]
= 79771.50524 Pa
= 79.772 kPa
The pressure drop = 79.772 kPa
The head loss in the pipe:
[tex]h_L = \dfrac{\Delta P_L}{\rho g}[/tex]
= [tex]\dfrac{79771.50524 }{999.1 * 9.81}[/tex]
= 8.14 m
The power input
[tex]W_{pump} = V\Delta P_L[/tex]
= 10 * 10^{-3} * 79771.50524
= 797.72 W
As temperature ____, molecular movement ____ , causing the distance between atoms to ____
a. deceases, increases, increase
b. Increases, increases, increase
c. decreases, increases, decrease
d. Increases, decreases, increase
Answer:
The correct answer is b.
A sound wave with a power of 8.8 × 10–4 W leaves a speaker and passes through section A, which has an area of 5.0 m2.
What is the intensity of sound in this area? (Intensity = I = )
1.8 × 10–4 W/m2
1.8 × 10–6 W/m2
1.6 × 10–4 W/m2
1.6 × 10–6 W/m2
Mark this and return
Answer: 1.8 x 10-4 W/m^2
Explanation:
