Answer:
Zero
Explanation:
At a projectile's highest point, its velocity is zero. At a projectile's highest point, its acceleration is zero
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Select ALL the correct answers.
Which of these factors make hydrogen fuel cells a better option than burning fossil fuels?
1.Hydrogen fuel cells have a higher energy efficiency.
2.Hydrogen fuel cells create less pollution.
3.Burning fossil fuels relies on outdated devices and technology.
4.Hydrogen is the most abundant element in the universe.
5.Hydrogen fuel cells are more expensive than fossil fuels.
Answer:
1) and 2)
Explanation:
Hydrogen fuel is very efficient. More energy is extracted from this fuel source than with conventional power technologies, according to Tobin Smith for Billion Dollar Green. Fossil fuels have a high combustion rate and are capable of releasing tremendous amount of energy.
A car started its motion from rest and accelerated for 7 seconds, with the acceleration of 3 m/s2. Then it was moving with a constant velocity for 8 seconds. What was the velocity of the car after 7+8 seconds?
PLEASE HELP ME
Answer:
Kejlshkdhh4hrbrldbd
HELP PLEASE!!! 15 POINTS
How does the speed of waves vary in different media?
Radio waves are used to transmit verbal messages through space.
IS THIS TRUE OR FALSEE???
What was not a positive benefit of Spanish exploration in Oklahoma?
A.
Future interactions between the Spanish and French would have a buffer zone.
B.
Historians gained a written account of Oklahoma in the 15th and 16th centuries.
C.
Geographers gained new knowledge about the continent of North America.
D.
The Spanish and American Indian tribes enjoyed exclusively friendly relations.
the answer is:
d. the spanish and american indian tribes enjoyed exclusively friendly relations.
Answer:
b. the spanish and american indian tribes enjoyed exclusively friendly relations.
Explanation:
PLEASE HELP!!
A person is traveling at 5m/s for around 20 minutes. how much distance did he cover? hint: change minutes to seconds.
A force of 75 N at an angle of 15° to the direction of motion moves a chair 3 m. Which change would result in more work being done on the chair?
using 60 N of force
moving the chair 2 m
increasing the angle to 20°
decreasing the angle to 10°
Answer:
decreasing the angle to 10°
Explanation:
correct on edge~ !
Answer:
Decreasing the angle to 10
Explanation:
When the force is calculated it is greater
Look at pic.... 2 examples of radiation and how they are radiation
Answer:21
Explanation:
what is one second time ?
Answer:
one second is defined au1/86400th the part of a solar day
which of the following is the same as 1 second
Answer:
theres no
Explanation:
picture or anything so... ur question doesnt make sense
If a racer maintained a constant speed, during which sections of the race would the racer's velocity be the same?
Sections 1 and 2
Sections 2 and 3
Sections 2 and 4
Sections 3 and 4
pls help!!
Answer:
Sections 3 and 4
Explanation:
The correct answer would be sections 3 and 4.
The velocity of an object is the speed of the object in a particular direction. In this case, the speed of the racer is constant irrespective of the distance or the direction. Hence, the sections of the race during which the racer's velocity would be the same would be the sections in which the racer faces the same direction - which is sections 3 and 4.
What are stars? Are their lights natural what is the biggest galaxy are there any other planets other then ours have scientists found the other proofs of Aliens.
Best Answer will get brainliest and gifted points
Answer:
Stars are huge celestial bodies made mostly of hydrogen and helium that produce light and heat from the churning nuclear forges inside their cores. Aside from our sun, the dots of light we see in the sky are all light-years from Earth.
Explanation:
Stars are the most widely recognized astronomical objects, and represent the most fundamental building blocks of galaxies. The age, distribution, and composition of the stars in a galaxy trace the history, dynamics, and evolution of that galaxy. Moreover, stars are responsible for the manufacture and distribution of heavy elements such as carbon, nitrogen, and oxygen, and their characteristics are intimately tied to the characteristics of the planetary systems that may coalesce about them. Consequently, the study of the birth, life, and death of stars is central to the field of astronomy.
Stars are born within the clouds of dust and scattered throughout most galaxies. A familiar example of such as a dust cloud is the Orion Nebula. Turbulence deep within these clouds gives rise to knots with sufficient mass that the gas and dust can begin to collapse under its own gravitational attraction. As the cloud collapses, the material at the center begins to heat up. Known as a protostar, it is this hot core at the heart of the collapsing cloud that will one day become a star. Three-dimensional computer models of star formation predict that the spinning clouds of collapsing gas and dust may break up into two or three blobs; this would explain why the majority the stars in the Milky Way are paired or in groups of multiple stars.
Answer:
stars are are giant balls of gases...yes their light is natural, it emits light due to chemical activities in the cor of star. We are living in the milky way and the nearest galaxy to us is Andromeda galaxy which is about 2.5x more larger than our galaxy, no there are no proofs for presence of aliens
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Why does an object slow down when going uphill
Please explain properly
Answer:
The change in speed on slopes is due to gravity. When going downhill, objects will accelerate (go faster), and when going uphill they will decelerate (slow down). On a flat surface, assuming that there is little friction, they will then maintain a constant speed.
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1 point
1)A 1 kg brick is carried to up the Eiffel Tower to the 275 m platform. How
much gravitational potential energy does it acquire?
Answer:
The gravitational potential energy is 2,750 Joules
Explanation:
Given the following data;
Mass of brick = 1kg
Height of Eiffel Tower = 275m
Potential energy can be defined as the energy possessed by an object due to its position.
Mathematically, potential energy is;
[tex] P = mgh[/tex]
Also, we know acceleration due to gravity = 10m/s2
[tex] P = mgh[/tex]
[tex] P = 1 * 275 * 10 [/tex]
P = 2750 Joules.
Hence, the gravitational potential energy the brick acquired is 2750 Joules.
i really need help please just answer at least one
Answer:
9) a = 25 [m/s^2], t = 4 [s]
10) a = 0.0875 [m/s^2], t = 34.3 [s]
11) t = 32 [s]
Explanation:
To solve this problem we must use kinematics equations. In this way we have:
9)
a)
[tex]v_{f}^{2} = v_{i}^{2}-(2*a*x)\\[/tex]
where:
Vf = final velocity = 0
Vi = initial velocity = 100 [m/s]
a = acceleration [m/s^2]
x = distance = 200 [m]
Note: the final speed is zero, as the car stops completely when it stops. The negative sign of the equation means that the car loses speed or slows down as it stops.
0 = (100)^2 - (2*a*200)
a = 25 [m/s^2]
b)
Now using the following equation:
[tex]v_{f} =v_{i} - (a*t)[/tex]
0 = 100 - (25*t)
t = 4 [s]
10)
a)
To solve this problem we must use kinematics equations. In this way we have:
[tex]v_{f} ^{2} = v_{i} ^{2} + 2*a*(x-x_{o})[/tex]
Note: The positive sign of the equation means that the car increases his speed.
5^2 = 2^2 + 2*a*(125 - 5)
25 - 4 = 2*a* (120)
a = 0.0875 [m/s^2]
b)
Now using the following equation:
[tex]v_{f}= v_{i}+a*t\\[/tex]
5 = 2 + 0.0875*t
3 = 0.0875*t
t = 34.3 [s]
11)
To solve this problem we must use kinematics equations. In this way we have:
[tex]v_{f} ^{2} = v_{i} ^{2} + 2*a*(x-x_{o})[/tex]
10^2 = 2^2 + 2*a*(200 - 10)
100 - 4 = 2*a* (190)
a = 0.25 [m/s^2]
Now using the following equation:
[tex]v_{f}= v_{i}+a*t\\[/tex]
10 = 2 + 0.25*t
8 = 0.25*t
t = 32 [s]
Explain how if a solid, liquid, and gas are put into individual containers how they fill the container.
Answer:
serial in which container is filled
Solid -base of container
Liquid- above solid
Gas- above liquid
Explanation:
If any mixture of matter in different state (that solid , liquid or gas )are kept in any container, then substance with higher density will be settled at lowest surface first and similarly the substance with lowest density will be at upper part of container.
In the given container we have to keep solid, liquid and gas
sold has the highest density,gas the lowest density andliquid has the density higher than gas but less than solid.based on this
solid will be at surface of container
above sold will be liquid
above liquid will be presence of Gas
serial in which container is filled
Solid -base of container
Liquid- above solid
Gas- above liquid
Two children are pulling and pushing a 30.0 kg sled. The child pulling the sled is exerting a force of 12.0 N at a 45o angle. The child pushing the sled is exerting a horizontal a force of 8.00 N. There is a force of friction of 5.00 N.
What is the weight of the sled?
(blank) N
What is the normal force exerted on the sled? Round the answer to the nearest whole number.
(blank) N
What is the acceleration of the sled? Round the answer to the nearest hundredth.
(blank) m/s2
Answer:
Explanation:
Find the diagram of the scenario in the attached file.
From the diagram, the weight = mass * acceleration due to gravity
mass of sled = 30.0kg
acc. due to gravity = 9.81m/s
weight of the sled = 30.0*9.81
weight of the sled = 294.3N
The normal reaction force R in the diagram will be gotten by resolving the 12N force along the vertical
Ry = 12sin45°
R = 12 * 1/√2
R = 12√2/√2
R = 6√2 N
R = 8.49N ≈ 9.0N
The normal force exerted on the sled is approximately is 9.0N
Get the acceleration
Using the formula [tex]\sum Fx = ma_x[/tex] where;
m is the mass of the sled = 30.0kg
[tex]a_x[/tex] is the acceleration of the sled
[tex]\sum Fx = 8 + 12cos45^0\\\sum Fx = 8 + 12(0.7071)\\\sum Fx = 8 + 8.49\\\sum Fx = 16.49N[/tex]
Substitute into the formula;
[tex]a_x = \frac{\sum Fx }{m} \\ a_x = \frac{16.49}{30}\\ a_x = 0.55 m/s^2[/tex]
Hence the acceleration of the sled rounded to the nearest hundredth is 0.55m/s²
what are two different examples of positive exeleration
Answer:Accelerating your car to get up to speed on a freeway
An airplane accelerating to take off
Accelerating out of the starting blocks at a track meet
Explanation:
Find the acceleration of a car with a mass of 1,200kg and a force of 11,000N
Answer:
42000N
Explanation:
.........................
What amount of force would be required to lift a 10 kg dog?
Answer:
5 Kg force I think try
Explanation:
the force is equal to the weight divided by two. It will require a 5 Kg force to lift a 10Kg weight.
4
Select the correct answer.
A car traveling south is 200 kilometers from its starting point after 2 hours. What is the average velocity of the car?
ОА.
100 kilometers/hour south
OB.
200 kilometers/hour
O C.
200 kilometers/hour north
OD
100 kilometers/hour
Reset
Next
The maximum tension that a 0.80 m string can tolerate is 15 N. A 0.35-kg ball attached to this string is being whirled in a vertical circle. What is the maximum speed the ball can have at the top of the circle? 3.74 m/s 9.67 m/s 5.86 m/s None of the above
Answer:
v=5.86 m/s
Explanation:
Given that,
Length of the string, l = 0.8 m
Maximum tension tolerated by the string, F = 15 N
Mass of the ball, m = 0.35 kg
We need to find the maximum speed the ball can have at the top of the circle. The ball is moving under the action of the centripetal force. The length of the string will be the radius of the circular path. The centripetal force is given by the relation as follows :
[tex]F=\dfrac{mv^2}{r}[/tex]
v is the maximum speed
[tex]v=\sqrt{\dfrac{Fr}{m}} \\\\v=\sqrt{\dfrac{15\times 0.8}{0.35}} \\\\v=5.86\ m/s[/tex]
Hence, the maximum speed of the ball is 5.86 m/s.
field lines point out from all sides on a object. Some of the lines point into a second object nearby. Which statement best describes the objects? A. both objects are permanent magnets B. both objects are electromagnets C. the first object is negatively charged, and the second object is positively charged D. the first object is positively charged, and the second object is negatively charged
Answer:
The first object is positively charged, and the second object is negatively charged. (D)
Explanation:
What is the depth of the crater if the time is 6.3 s? An astronaut stands by the rim of a crater on the moon, where the acceleration of gravity is 1.62 m/s2. To determine the depth of the crater, she drops a rock and measures the time it takes for it to HIT the bottom
Complete Question
An astronaut stands by the rim of a crater on the moon, where the acceleration of gravity is 1.62 m/s2. To determine the depth of the crater, she drops a rock and measures the time it takes for it
to hit the bottom. If the time is 6.3 s, what is the depth of the crater?
Answer:
The depth is 32 m
Explanation:
From the question we are told that
The time is t = 6.3 s
The acceleration due to gravity is [tex]g = 1.62 \ m/s^2[/tex]
Generally from kinematic equation
[tex]s = ut + \frac{1}{2} - at^2[/tex]
Here the u is the initial velocity and the value is 0 m/s
[tex]s = 0 + \frac{1}{2} - (1.62) * (6.3)^2[/tex]
[tex]s = 32 \ m [/tex]
A 250 kg cannon containing a cannonball is initially at rest. If the cannon shoots the 20 kg cannonball at 15 m/s, what is the magnitude of the recoil velocity of the cannon?
Answer:
hhgyujhkhgjghhjhhghjkhlhjkghghgh
Explanation:
If your speed is 3 meters in 1 second (3m/s), how long would it take you to go 15
meters?
Answer:
5 seconds
Explanation:
Answer:
5 seconds
Explanation:3=1 6=2 9=3 12=4 15=5 15 equal 5 mean 15 meters in 5 sec
When the white ball strikes the other colored balls, what can you say about the total momentum of all of the balls combined?
Momentum is never created or destroyed. It is conserved.
The cue stick gave the cue ball all the momentum there is on the table. There's nothing on the table that can pour in any more momentum.
After the strike, with 15 or 16 balls rolling every which way around the table, the total momentum of all of them combined will be the same as the cue ball's momentum right now, before the strike.
One particle has a charge of 4.2 x 10-°C, while another particle has a charge
of 1.10 10-9 C. If the two particles are separated by 0.005 m, what is the
electromagnetic force between them? The equation for Coulomb's law is
F = kongs, and the constant, k, equals 9.00 x 10°Nm2/C2
Answer:
1.66*10^-3N
Explanation:
Two objects gravitationally attract with a force of 18.0 N. If the mass of one of these objects is doubled, the new force of attraction is ____ N.
Two objects gravitationally attract with a force of 18.0 N. If the mass of both of these objects is doubled, the new force of attraction is _____ N.
Two objects gravitationally attract with a force of 18.0 N. If the mass of one of these objects is tripled, the new force of attraction is _____ N.
Two objects gravitationally attract with a force of 18.0 N. If the mass of both of these objects is tripled, the new force of attraction is ______ N.
Two objects gravitationally attract with a force of 18.0 N. If the mass of one of these objects is quadrupled, the new force of attraction is ____N.
Two objects gravitationally attract with a force of 18.0 N. If the mass of both of these objects is quadrupled, the new force of attraction is ____N
A sudent is given an example of an unknown liquid in the laboratory the student thinks that the liquid is water what which of the following properties of the sample is most helpful to determine the if the liquid is water
Answer:
Color. Smell?
Explanation:
Answer:
Freezing Point or Boiling Point
Explanation:
Hope this helps!
Use what you learned in the passage to
determine which pitcher's fastball has
the average speed.
A. Dennis, 60 feet in 0.5 seconds
B. Johnny, 60 feet in 0.45 seconds
C. Travis, 60 feet in 0.52 seconds
D. Michael, 60 feet in 0.48 seconds
Dennis, 60 feet in 0.5 seconds is the average speed of a pitcher's fastball. So, the correct option is (A).
What is the Average speed?Average speed is defined as the total distance covered by the object in a particular time interval. Average speed is a scalar quantity which is represented by the magnitude and not the direction.
The formula for average speed is found by calculating the ratio of the total distance traveled by the body to the time taken to cover that distance which is expressed as:
Average speed= Total distance travelled/ Time taken
The unit of the average speed is meter/second.
In the above given information, the pitcher's fastball average speed of Dennis is 120
Thus, Dennis, 60 feet in 0.5 seconds is the average speed of a pitcher's fastball. So, the correct option is (A).
Learn more about Average speed, here:
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