Answer:
is that a question or a statement lol
Explanation:
While delivering 125 kg blocks of ice to a local village, Kristoff and his family (and Sven too) come upon a cliff that is 5.7 m above them. To solve their problem, they build a catapult that will launch their blocks of ice with an initial velocity of 15 m/s and at an angle of 45 degrees above the ground.
Prove that the catapult will successfully launch the ice blocks up to the top of the cliff. Quantities you will need to solve for will be initial vertical velocity, horizontal velocity, the distance the catapult is from the cliff, and the amount of time it takes the ice to reach the cliff. Assume that they are experts and have arranged everything so that the ice blocks just barely reach the top of their parabolic path when they land at the top of the cliff and make a smooth landing. Draw a picture of the scene to help you visualize what is happening.
After landing on the flat land above, each block of ice travels 20 meters while slowing to a stop.
What is the rate of acceleration while the blocks slow to a stop?
How long do the blocks take to slow to a stop?
What is the amount of friction between the ice and the snowy ground?
How long do the blocks take to slow to a stop?
What is the amount of friction between the ice and the snowy ground?
Answer:
a. Since h = 5.74 m > 5.7 m, the height of the cliff, the block of ice will successfully launch to the top of the cliff.
b. -2.81 m/s²
c. 3.78 s
d. -351.25 N
Explanation:
a. After landing on the flat land above, each block of ice travels 20 meters while slowing to a stop.
For the block of ice to reach the top of the cliff, its maximum height, h should be greater than or equal to 5.7 m. That is, h ≥ 5.7 m.
The maximum height of a projection h, projected with an initial velocity v at an angle Ф is h = v²sin²Ф/2g where g = acceleration due to gravity = 9.8 m/s².
For the block of ice, v = 15 m/s and Ф = 45°. So,
h = v²sin²Ф/2g
= (15 m/s)²sin²45/(2 × 9.8 m/s²)
= 225 (m/s)²(1/√2)²/19.6 m/s²
= 225 (m/s)²(1/2)/19.6 m/s²
= 112.5 (m/s)²/19.6 m/s²
= 5.74 m
Since h = 5.74 m > 5.7 m, the height of the cliff, the block of ice will successfully launch to the top of the cliff.
The graph is in the attachment.
b. What is the rate of acceleration while the blocks slow to a stop?
Using v² = u² + 2as where u = initial horizontal velocity of block = 15m/scos45° = 10.61 m/s, v = final velocity of block = 0 m/s since it stops, a = acceleration and s = distance block moves = 20 m
So, a = (v² - u²)/2s
substituting the variables into the equation, we have
a = ((0 m/s)² - (10.61 m/s)²)/2(20 m)
= - 112.57 (m/s)²)/40 m
= -2.81 m/s²
c. How long do the blocks take to slow to a stop?
Using v = u + at where u = initial horizontal velocity of block = 10.61 m/s v = final velocity of block = 0 m/s since it stops, a = acceleration = -2.81 m/s² and t = time it takes block of ice to stop
So, making t subject of the formula,
t = (v - u)/a
substituting the values of the variables, we have
t = ( 0 m/s - 10.61 m/s)/-2.81 m/s²
= -10.61 m/s/-2.81 m/s²
= 3.78 s
d. What is the amount of friction between the ice and the snowy ground?
The frictional force, f = net force on block of ice
f = ma where m = mass of bock = 125 kg and a = acceleration of block = -2.81 m/s²
f = ma
= 125 kg(2.81 m/s²)
= -351.25 N
what is not a raquet sport
Answer:
what
Explanation:
Racket sports include tennis, badminton, squash or any other sport where you use rackets to hit a ball or shuttlecock to play. They can be played competitively or just for fun and are a great form of physical activity.
th weight of an object is
Answer:
the weight of an object is the force acting on the object due to gravity. the gravitational force acting on the object. Others define weight as a scalar quantity, the magnitude of the gravitational force.
Explanation:
A sign is attached to the side of a building as seen below. The sign is attached to a steel rod. A wire connects to the end of the rod for support. The mass of the sign is 50 kg. Determine the supporting force exerted by the cable
Answer:
500N
Explanation:
50kgx10N/kg
= 500N
According to Kepler's second law of planetary motion,
O a. planets maintain constant speed around the Sun.
Ob. the area swept out by the orbit per time unit keeps changing.
O c. the speed of a planet is greatest when it is closest to the Sun.
O d. planets maintain constant acceleration around the Sun.
Answer:
c. the speed of a planet is greatest when it is closest to the Sun.
Explanation:
Johannes Kepler was an astronomer who discovered that planets had elliptical orbits in the early 1600s (between 1609 and 1619).
The three (3) laws published by Kepler include;
I. The first law of planetary motion by Kepler states that, all the planets move in elliptical orbits around the Sun at a focus.
II. According to Kepler's second law of planetary motion, the speed of a planet is greatest when it is closest to the Sun.
Thus, the nearer (closer) a planet is to the Sun, the stronger would be the gravitational pull of the sun on the planet and consequently, the faster is the speed of the planet in terms motion.
III. The square of any planetary body's orbital period (P) is directly proportional to the cube of its orbit's semi-major axis.
Answer:
A planet moves faster when it is closer to the Sun.
Explanation:
Kepler law!
1 point
A leak in a swimming pool allows 2.50 liters to flow out every minute. How
many gallons leak out in week? (There are 0.946 liters per quart and 4
quarts per gallon.) *
O 910. gallons
O 12 700 gallons
0 7 140 gallons
6 660 gallons
Answer:
66.6 G
Explanation:
In one of his many action movies Jackie Chan jumped off a building by wrapping a rope around his waist and then allowed it to unwind as he fell to the ground, much the same as a yo-yo. Assuming his acceleration toward the ground was a constant much less than g, the tension in the rope would be
Joe and Jim start at rest at the starting line of a race track. Both runners accelerate at the same rate, but Joe accelerates for twice as long as Jim. Describe the final speed of Joe compared to Jim.
Answer:
Vf₂ = 2 Vf₁
It shows that final speed of Joe is twice the final speed of Jim.
Explanation:
First, we analyze the final speed of Jim by using first equation of motion:
Vf₁ = Vi + at
where,
Vf₁ = final speed of Jim
Vi = initial speed of Jim = 0 m/s
a = acceleration of Jim
t = time of acceleration for Jim
Therefore,
Vf₁ = at ---------------- equation (1)
Now, we see the final speed of Joe. For Joe the parameters will become:
Vf = Vf₂
Vi = 0 m/s
a = a
t = 2t
Therefore,
Vf₂ = 2at
using equation (1):
Vf₂ = 2 Vf₁
It shows that final speed of Joe is twice the final speed of Jim.
Alex wants to learn how to surf, but he is not a strong swimmer. He knows he needs to increase his ability to paddle out in order to catch the best waves. Which piece of advice would you give to help him get started on reaching his goal? He should swim at least three times a week at the community pool to build stamina. He should tread water every day to get more comfortable in the water. He should purchase the best surfboard he can afford because it will help him paddle faster. He should watch your friend who is a competitive surfer practice to learn her technique.
Answer:
He should swim at least three times a week at the community pool to build stamina.
Explanation:
---Spring Question---
A 0.84 kg ball is held at rest against a spring (k = 142 N/m) that has been compressed 0.06 m. The ball and spring are on a table and the ball is 2.0 m above the ground. If friction between the ball and the table is negligible, then how far from the edge of the table (in meters) will the ball hit the ground?
Answer:
The distance from the edge of the table at which the ball will hit the ground is approximately 0.49 meters
Explanation:
The mass of the ball = 0.84 kg
The spring constant k = 142 N/m
The compression of the spring = 0.06
Therefore, by conservation of energy, we have;
The potential energy of the spring = The kinetic energy given to the ball
The potential energy of the spring = 1/2 × k × x² = 1/2 × 142 × 0.06² = 0.2556
The potential energy of the spring = 0.2556 J
The kinetic energy given to the ball = 1/2 × m × v²
Where;
v = The final velocity of the ball
Substituting gives;
1/2 × 0.84 × v² = 0.2556
∴ v = √(0.2556/(1/2 × 0.84)) ≈ 0.78
The final velocity of the ball = v ≈ 0.78 m/s
The height of the ball above the ground, h = 2.0 m
Therefore, we have;
The time, t, it takes the ball to touch the ground from the 2.0 m height, h, is given as follows;
h = 1/2·g·t²
t = √(2·h/g)
Where;
g = The acceleration due to gravity = 9.81 m/s²
∴ By substitution, we have;
t = √(2 × 2/9.81) ≈ 0.63855
t ≈ 0.63855 s
The distance from the edge of the table at which the ball will hit the ground = The horizontal distance covered during before the ball hits the ground
The horizontal distance covered during before the ball hits the ground = The (horizontal) velocity of the ball × The time it takes the ball to touch the ground
∴ The horizontal distance covered during before the ball hits the ground = 0.78 × 0.62855 ≈ 0.490269 ≈ 0.49
The distance from the edge of the table at which the ball will hit the ground = The horizontal distance covered during before the ball hits the ground ≈ 0.49 m
A 10 kg object experiences an acceleration of 2 m/s squared. What net force was applied to the object?
F = ma
= 10kg × 2m/s
= 20N
Answer : 20N
Explanation :
F = Force (N)
m = mass (kg)
a = acceleration (m/s)
A fish swimming at a rate of .6 m/s notices a huge shark. Three seconds later, the fish is swimming at a speed of 3 m/s. What is the fish's acceleration?
0.8 m/s/s
-0.8 m/s/s
12.5 m/s/s
-12.5 m/s/s
Answer:
C
Explanation:
???
i think
Directions: Summarize the main ideas of this lesson by answering the question below.
How might a person acquire a fear of or aversion to something even though it has no negative effect
on him or her?
Answer:
Explanation:
Trypophobia is a fear or disgust of closely-packed holes. People who have it feel queasy when looking at surfaces that have small holes gathered close together.A person may start by imagining what they fear, then looking at pictures of the fear object, and then finally being near or even touching the source of their anxiety. In the case of trypophobia, a person with symptoms may start by simply closing his eyes and imagining something such as a honeycomb or seed poThey can help you find the root of the fear and manage your symptoms. Last medically reviewed on July 20, 2017 Medically reviewed by Timothy J. Legg, Ph.D., CRNP — Written by Annamarya Scaccia ...
A race car makes one lap around a track with a radius of 41 meters in 8 seconds. What is the velocity?
Answer:
31.21 m/s
Explanation:
radius=41m
time = 8 sec
circumference=2πr
from formula
circumference=2×22/7×41
=257.71m
now
velocity=total distance( circumference)/total time
=257.71/8
= 32.21m/s
The velocity of race car makes one lap around a track with a radius of 41 meters in 8 seconds is 32.19 m/s
What is velocity ?Velocity is "rate of change of displacement with respect to time".
i.e. v= dx/dt
it is also defined as displacement over time. i.e. v=Displacement/Time.
Velocity shows how much distance can be covered in unit time. It's SI unit is m/s. It is vector quantity ( having both direction as well as momentum). where displacement is distance from mean position.
Given,
Radius of the track r= 41m
time taken by car to complete one lap T = 8s
velocity v = ?
we know that ω = 2π÷T
ω = 2×3.14 ÷ 8
ω = 0.785 rad/s
v=rω
v= 41×0.785
v= 32.185 ≅32.19 m/s
Hence velocity of the car is 32.19 m/s
To know more about velocity, click :
https://brainly.com/question/17127206
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A crate is being pulled down an incline as shown in the figure. With respect to the crate's direction of motion, which of the following forces does only negative work on the crate?
Answer:Fn
Explanation:
1. A student notices that wearing darker colors in sunlight makes him feel warmer, so he decides to conduct an experiment. He takes five pieces of different-colored cloth and wraps
each one around a water bottle. He then places all five bottles in direct sunlight and measures the temperature of the water in each bottle an hour later.
What should be kept constant throughout this experiment?
O the color of the cloth
O the temperature of the water
the amount of water in each bottle
O the temperature of the outside air
Answer: the color of the cloth
Explanation:
Which statement is true?
Every magnesium (Mg) atom has atomic number of 12.
Every magnesium (Mg) atom has a mass number of 24.
this is science but i just put physics
Answer:
Every magnesium (Mg) atom has atomic number of 12.
Explanation:
Magnesium (Mg) is a chemical element of great importance for plants, animals, and humans.
Alkaline earth metal, magnesium is obtained by electrolysis of magnesium chloride solution.
Magnesium burns with a shining flame. Magnesium is a good reducing agent. This property is used to obtain some other metals.
A car drives 500m in 2 minutes.What is the cars speed? A.2m/s B.4m/s C.5 m/s
Answer:
B
Explanation:
1 minute = 60 seconds
2 minutes = 2 * 60 = 120 seconds.
d = r * t
t = 120 seconds
d = 500 meters
r = d/t
r = 500 / 120 = 4.167 m/s
The closest answer is B
help me with this please :((
Answer:
huh?
Explanation:
If u drop a bar of soap on the floor then is the floor clean or is the bar of soap dirty? Lol I’m so bored i dont even know what I’m doing.
Answer:
CLEAN
Explanation:
Answer:
I just wash mine with water when I drop it . That is a good question tho :)
Explanation:
According to the Natural Resources Defense Council, what is the largest contributor to land pollution?
According to the Natural Resources Defense Council, activities related to
production are the largest contributor to land pollution.
Answer: Food
Explanation:
Food is the largest contributor to land pollution.
What is the Natural Resources Defense Council?
NRDC strives to rid our food, air, water, and household products from toxic chemicals.
40 percent of food produced in the US is trashed each year according to the Natural Resources Defense Council.
Food decomposes anaerobically and releases methane emissions, a greenhouse gas that is 28 times more potent than carbon dioxide over a 100-year period and 84 times more on a 20-year scale , when food waste ends up in landfill.
Worldwide, some percent of greenhouse gas emissions result from food waste alone.
Therefore,
Food is the largest contributor to land pollution.
Learn more about NRDC here:https://brainly.com/question/14538949
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URGENT! 40 POINTS! For each situation below, find the work done on the box using both energy and forces.
1. A 2 kg box initially at rest slides down a frictionless ramp (at 15ᵒ from the ground) for
1 second.
2. A 2 kg box is thrown upward with an initial speed of 3.5 m/s. Consider the box from
the time it was thrown until it reaches its maximum height.
3. A 2 kg box is dropped from an initial height of 10 m.
I have some physics, I just don't know what formulas to use or where to start. Help is much appreciated.
Answer:
i’m not sure one second let me try to figure it out
Explanation:
!!!!!
While following directions on a treasure map, a person walks 45.0 m south, then turns and
walks 7.50 m east. What is the direction of the straight line that the treasure hunter could have
walked directly from the starting to reach the same spot?
(1 Point)
9.5° south of east
9.5° east of south
21° south of east
21° east of south
Answer:
46 m at 9.5 degrees east of south
Explanation:
Es muy común que cuando se viaja hacia un río o lago se juegue "ranita", el cual consiste en lanzar una piedra horizontalmente hacia adelante para que cuando ésta toque la superficie del agua haga varios "saltos" sobre el agua. Durante un juego de estos, un desocupado nota que una de las piedras que arroja se demora 0,4 s en tocar la superficie del agua y la toca a 2,5 m de la orilla del lago, desde donde fue lanzada. Encuentre: a) La altura de la que fue lanzada la piedra. b) La velocidad con la que fue lanzada.
Answer:
a) La piedra es lanzada desde una altura de 0,785 metros.
b) La piedra es lanzada con una velocidad inicial de 6,25 metros por segundo.
Explanation:
a) Dado que la piedra es lanzada horizontalmente, tenemos que la piedra experimenta un movimiento horizontal a velocidad constante y uno vertical uniformemente acelerado debido a la gravedad. La altura de la que fue lanzada la piedra se puede determinar mediante la siguiente ecuación cinemática:
[tex]y = y_{o}+v_{o,y}\cdot t +\frac{1}{2}\cdot g\cdot t^{2}[/tex] (1)
Donde:
[tex]y[/tex] - Altura final, medida en metros.
[tex]y_{o}[/tex] - Altura inicial, medida en metros.
[tex]v_{o,y}[/tex] - Componente vertical de la velocidad inicial, medida en metros por segundo.
[tex]t[/tex] - Tiempo, medido en segundos.
[tex]g[/tex] - Aceleración gravitacional, medida en metros por segundo cuadrado.
Si sabemos que [tex]y = 0\,m[/tex], [tex]v_{o,y} = 0\,\frac{m}{s}[/tex], [tex]t = 0,4\,s[/tex] y [tex]g = -9,807\,\frac{m}{s^{2}}[/tex], entonces la altura inicial de la piedra es:
[tex]y_{o} = y-v_{o,y}\cdot t -\frac{1}{2}\cdot g\cdot t^{2}[/tex]
[tex]y_{o} = 0\,m-\left(0\,\frac{m}{s} \right)\cdot (0,4\,s)-\frac{1}{2}\cdot \left(-9,807\,\frac{m}{s^{2}} \right) \cdot (0,4\,s)^{2}[/tex]
[tex]y_{o} = 0,785\,m[/tex]
La piedra es lanzada desde una altura de 0,785 metros.
b) Ahora, obtenemos el componente horizontal de la velocidad inicial a partir de la siguiente ecuación cinemática:
[tex]v_{o,x} = \frac{x-x_{o}}{t}[/tex] (2)
Donde:
[tex]x_{o}[/tex], [tex]x[/tex] - Posiciones horizontales iniciales y finales, medidas en metros.
[tex]t[/tex] - Tiempo, medido en segundos.
Si tenemos que [tex]x_{o} = 0\,m[/tex], [tex]x = 2,5\,m[/tex] y [tex]t = 0,4\,s[/tex], entonces el componente horizontal de la velocidad inicial es:
[tex]v_{o,x} = \frac{2,5\,m-0\,m}{0,4\,s}[/tex]
[tex]v_{o,x} = 6,25\,\frac{m}{s}[/tex]
La piedra es lanzada con una velocidad inicial de 6,25 metros por segundo.
How does seeing an object compare with seeing a shadow?
Answer: shadows are not parts of their objects—we can change a shadow without changing the object
Answer:
So we can see objects by seeing silhouettes. By contrast, shadows are not parts of their objects—we can change a shadow without changing the object (say, by putting another object in between the object and the light source). So we cannot see objects by seeing shadows.
Your maximum heart rate is the maximum number of times your heart can contract in one minute
True or false
Answer:
True
Explanation:
It is true i am right
Four measurements of the file card's width are made. Of the measurements given below, the LEAST precise.
O 7.62
O 7.63
O 7.34
O 7.6
In a place covered by shadow of cloud sun cannot be seen . Explain with reasons .
Answer:
Because even though our eyes have a huge dynamic range (ability to pick out details in sharply lit and lesser lit areas simultaneously) than any camera, there's a limit.
When there's strong sunlight, your pupils contract and let less light in, which makes the shadows look darker.
When it's cloudy, your pupils widen and let more light in, which makes the shadows look less dark.
Do some experiments with a camera and you'll soon get the hang of it.
NOTE: Also test HDR (high dynamic range) photography, where the camera takes three or more pictures in quick succession, with different exposure settings, and combines them to get the most detail of both bright and dark areas. The result is more or less what we percieve.
Why is a teacher's feedback valuable?
Answer:
Because they could help you move on better with your strategy and ultimately get you better scores on tests
Answer:
Through feedback, teachers can provide the students with suggestions for development, learning strategies and corrections for errors. The importance of constructive feedback allows for many positive opportunities. This component also enhances a student's self-efficacy and provides an avenue for motivation.
Which best represents the appearance of the moon on July 25, 2011
Answer:
Its the third quarter or waning quarter
Hope this helps :3