Answer:
The modern periodic table of elements contains
Eighteen main groups.
distance travelled by a train is 495 km in 4 hours 30 minutes, what is its speed in m/s?
Answer:
9.09m/s
Explanation:
Speed = Distance/Time
Distance = 495km
Time = 4 hr 30 min = 4 hr 1/2hr = 4.5 hr
Therefore, Speed = 495/4.5 = 110km/h
Now to convert km/h to m/s
110 x 1000/ 110 x 110
110 cancels out each other, we are now left with
1000/110 = 9.09m/s
Which types of changes observe the law of conservation of mass?
A.only changes of state
B.only physical changes
C.only chemical changes
D.physical changes and chemical changes
Answer:
I think it might be umm... b
The correct answer is actually D
Explanation: i got it right on my district assignment! :)
what is the speed of a car that travels a distance of 200m in 2.3 seconds ?
Answer:
460metre per second
Explanation:
Speed = Distance x Time.
Evidence of a chemical change includes
A) change in size.
B) change in color.
C) change in shape.
Eliminate
D) change in weight.
Evidence of a chemical change includes
change in color
An airplane accelerates down a runway at 3.10m/s^2 for 41.5 seconds from rest until it finally lifts off the ground . What is the displacement before take off
Answer:1720m
Explanation:
Uh
Represent the following sentence as an algebraic expression, where "a number" is the
letter x. You do not need to simplify.
The product of 5 and the difference of 9 and a number.
Answer:
não sei.................
One fifth of the difference between a number and one is given to us in this line. This must be written as an algebraic expression. Now that this number is expressed as a letter x difference.
What algebraic expression number is the letter x?Thus, a number that is 5 more than x is equal to x+5. As a result, “5 more than a number” is represented by the algebraic expression “x+5”. The right response is therefore “x+5”.
We don't know what the value of the variable x is, but it can have any value. Since it is a constant number that is utilized with the variable term and is clearly defined, 5 is referred to as the coefficient of x.
Therefore, It can be calculated as 1, divided by 5, multiplied by the entity that is present. For the response to the query is 1 multiplied by x, minus 1, multiplied by 5 divided by 1.
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What do all of the elements in group 13 have in common?
What aspect of motion can you conclude is common among freely falling objects ?
Answer:
Free-fall is defined as the movement where the only force acting on an object is the gravitational force.
By the second Newton's law, we have that:
F = m*a
Where F = Force, m = mass, a = acceleration.
We can write this as:
a = F/m
And the gravitational force can be written as:
F = (G*M/r^2)*m
Where G is the gravitational constant, M is the mass of the Earth in this case, and r is the distance between both objects (the center of the Earth and the free-falling object)
As the radius of the Earth is really big, the term inside the parentheses is almost constant in the region of interest, then we can write:
G*M/r^2 ≈ g
And the gravitational force is:
F = g*m
And by the second Newton's law we had:
a = F/m = (g*m)/m = g
a = g
Then the acceleration does not depend on the mass of the object.
Then the thing that is common among the free-falling objects is the vertical acceleration.
HELP. A river flows South with a speed of 8m/s. From the shore, you see a boat moving South with a speed of 10 m/s. From their frame of reference, how fast are the rowers moving?
Answer:
18 m/s
Explanation:
Given that,
Speed of river is 8 m/s due South
From the shore, you see a boat moving South with a speed of 10 m/s. Both boat and river are moving in same direction. The resultant velocity will add up.
v = 10 m/s + 8 m/s
v = 18 m/s
Hence, the rowers are moving with a speed of 18 m/s.
differenciate between emf and potential difference
Answer: 1.Emf is the total voltage in the battery while the potential difference is the work done in moving a charge against the electric field between two specific points in the circuit. 2.Emf is always greater than the potential difference.
Explanation:
To me (electrical engineer since 1973), there is no difference. They are two different names for the same thing.
Can you ever absolutely prove that a hypothesis is correct? Explain.
Yes you can, with using scientific experiment.
Ask a question -- Do background Research -- Construct a Hypothesis --Test with an Experiment -- Procedure working? -- Yes or no? -- Analyze Data and Draw Conclusions
With an experiment you can discover if its correct or not.
Hope this helps ! <3
A plane takes off at an angle of 30 degrees at a speed of 150 km/h. Determine the horizontal
and vertical components of this velocity vector.
Answer:
Horizontal Component = 129.9 km/h
Vertical Component = 75 km/h
Explanation:
When a vector is resolved on the x-axis and the y-axis, the components so formed are called its rectangular components. The component along y-axis is called the vertical component and the component along x-axis is called horizontal component. These components can be given by following formulae:
Horizontal Component = v Cos θ
Vertical Component = v Sin θ
where,
v = velocity = 150 km/h
θ = angle = 30°
Therefore,
Horizontal Component = (150 km/h)(Cos 30°)
Horizontal Component = 129.9 km/h
Vertical Component = (150 km/h)(Sin 30°)
Vertical Component = 75 km/h
in general, as the human population increases which of the following is true? OA The amoum of habitat destroyed by people decreases OB. The sound of clean water available for use increases. OC. The amount of waste produced by people decreases D. The amount of resources used by people increases
in your ans
A jogger runs the first 250 m of a race in 13.5 sec. What is the jogger's
velocity(m/s)?
Answer:
S=250 m
t=13.5 sec
V=?
Explanation:
V=S/t
V=250/13.5
V=18.51m/s
What kind of things would Physics be able to answer? I. How does a hair dryer work? II. How does a lightning bolt form? III. How far will a cannon ball fly through the air? IV. What happens to a person after they die? I and III I, II, and III I only I, II, IV
Answer:
physics answers everything to understand biology you need to understand chemistry which is connected to physics which is connected to mechanics like fluid mechanics or quantum mechanics which is connected to math and all of that is science not particularly physics but physics can answer all of the questions you asked and more.
Explanation:
Answer:
sorry im only in fifth grade
Explanation:
A speed racer travels 25.3 m/s in 9.6 s. How far did it travel?
Speed = 25.3 m/s
Time taken = 9.6 s
To be calculated:-Calculate the distance covered by a body.
Formula applied:-Speed = Distance/Time
Solution:-We know,
Speed = Distance/Time
[tex] \bf\implies \: 25.3 = \frac{Distance}{9.6} [/tex]
[tex] \bf \implies \: Distance = 25.3 \times 9.6[/tex]
[tex] \bf\implies \: Distance = 242.88 \: m \: (approx)[/tex]
You accidentally throw your car keys horizontally at 8.0 m/s from a cliff. If yours keys land 28 m from the base of the cliff, how high was the cliff? Question 10 options: 17.15 m 60 m 45 m 28 m
Answer:
[tex]45m[/tex]
Explanation:
Let [tex]V_0[/tex] be the horizontal speed of the keys and D be the horizontal distance covered by the keys.
[tex]V_0= 8.0 \frac ms[/tex]
[tex]D= 28 m[/tex]
The initial velocity in the vertical direction is [tex]0[/tex].
Let [tex]g[/tex] be the acceleration due to gravity, which always acts vertically downwards, so, it will not change the horizontal direction of the speed, i.e. [tex]V_0[/tex] will remain constant throughout the projectile motion.
Let [tex]t[/tex] be the total time of flight in seconds. So,
[tex]D= V_0t[/tex]
[tex]\Rightarrow 28=8t[/tex]
[tex]\Rightarrow t=3 s \; \cdots (i)[/tex]
Let [tex]H[/tex] be the hight of the cliff.
Now, from the equation of motion
[tex]s=ut+\frac 1 2 at^2\;\cdots(ii)[/tex]
Where is the displacement is the direction of force, is the initial velocity in the direction of force, is the constant acceleration due to force and is the time of flight.
Here, , and (negative sign is for taking the sigh convention positive in the direction as shown in the figure.)
From equation (ii)
[tex]-H=0\times t + \frac 1 2 (-g)t^2[/tex]
[tex]\Rightarrow H= \frac 1 2 gt^2[/tex]
Take [tex]g= 10 \frac m{s^2}[/tex] and put the value of [tex]t[/tex] from equation (i), we have
[tex]H=\frac 1 2 \times 10\times 3^2[/tex]
[tex]\Rightarrow H= 45 m[/tex].
Hence, the height of the cliff was [tex]45 m[/tex].
Which of the following elements are found in Group 1A (sometimes referred
to as Group 1)?
Check all that apply.
A. Potassium
B. Argon
C. Hydrogen
D. Krypton
Answer:
A. Potassium
C. Hydrogen
Explanation:
A baseball player throws a baseball at 42 m/s. If the other player catching the baseball is 18 m from the player, how much time does it take the baseball to reach him?
Divide the distance by the speed:
(18 m) / (42 m/s) = 3/7 s ≈ 0.43 s
A block has two forces on it. One force is 15 N going north and the other is 22 N going east. What is the overall force pushing on the block with magnitude and direction?
Answer:
The overall force pushing on the block is 26.63 N in the direction of N 34° E
Explanation:
Given;
force going north, F₁ = 15 N
force going east, F₂ = 22 N
The resultant of the two forces is the hypotenuse side of the right angled triangle formed by the two forces.
Let the magnitude of the resultant force = F
F² = F₁² + F₂²
F = √(F₁² + F₂²)
F = √(15² + 22²)
F = 26.63 N
The direction of the force is the angle between the resultant force and the horizontal force.
tan θ = 15 / 22
tan θ = 0.6818
θ = tan⁻¹ ( 0.6818)
θ = 34°
Therefore, the overall force pushing on the block is 26.63 N in the direction of N 34° E
2. On a par 4 golf course, you make the ball in:
1. Hole in one
2. Birdie
3. Par
4. Eagle
5. Double bogey
6. Triple bogey
7. Bogey
a. 7 shots from the tee
b. 5 shots from the teel
c. 1 shot from the tee
d. 4 shots from the tee
e. 3 shots from the tee
f. 2 shots from the tee
g. 6 shots from the tee
The nucleus of most atoms is composed of which of the following sub-atomic particles?
Answer:
protons (+ charge) & neutrons (neutral charge)
however protons has a positive charge so it determined what atom it is.
Answer:
tightly packed protons and neutrons
Explanation:
Two grocery carts have the same initial total momentum. The two carts collide, and now cart B has a greater final velocity.
Which best describes the final total momentum of both the carts compared to the initial total momentum?
It is less if cart B has a smaller mass.
It is greater if cart B has a greater mass.
It is the same if no external forces are added.
It depends on the masses of cart A and cart B.
Answer: The anser is C
Explanation:
It is the same if no external forces are added.
Based on the principle of conservation of linear momentum, the final total momentum of both carts compared to the initial total momentum is the same if no external forces are added.
The given information;
two carts have equal initial momentum beforeafter collision, cart B has greater final velocityAccording to the principle of conservation of linear momentum, the total momentum before collision is equal to the total momentum after collision.
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
where;
m₁ and m₂ are the masses of the two cartsu₁ and u₂ are the initial velocities of the two cartsv₁ and v₂ are the final velocities of the two carts after collisionThus, based on this principle (conservation of linear momentum), the final total momentum of both carts compared to the initial total momentum is the same if no external forces are added.
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What information does a distance time graph provide
Why do we insulate houses?
A. To prevent heat transfer from inside to
the outside
B. To allow energy to flow from inside to
the outside
C. To keep them cool in the winter and
warm in the summer
For work to be accomplished we must have?
A. an action which causes movement and an opposite reaction
B. an action which causes no movement or reaction
C. a force and a movement in the opposite direction of the force
D. a force and a movement in the same direction as the force
Answer:
a force and a movement in the same direction as the force.
Explanation:
Which changes would result in a decrease in the gravitational force between two objects? Check all that apply.
increasing the distance between the objects
decreasing the distance between the objects
increasing the mass of one of the objects
increasing the mass of both objects
decreasing the mass of one of the objects
decreasing the mass of both objects
Answer:
- increasing the distance between the objects
- decreasing the mass of one of the objects
- decreasing the mass of both objects
Explanation:
Got it right on Edge 2020.
The gravitational force is decreased by increasing the distance between the objects or decreasing mass of one or both of the objects
According to Newton's law of Universal Gravitation; The force of gravity is directly proportional to the product of the masses between two bodies and inversely proportional to the square of the distance between them.
F = Gm1m2/r^2
Where;
G = gravitational constantm1 and m2 are the masses of the objects r = distance separating the objects.F = gravitational forceWe can see from the formula above, that the following will result in the decrease of the force between two objects;
increasing the distance between the objects decreasing the mass of one of the objects decreasing the mass of both objectsLearn more: https://brainly.com/question/999862
How many millimeters are in .075cm ?
Answer: 0.75
Explanation:
take away the 0
give reason the si syetem of units is better than the mks system
is there a tutor available
On what factors does the quantity of heat of an object depend?
Explanation:
This quantity is known as the specific heat capacity (or simply, the specific heat), which is the heat capacity per unit mass of a material. Experiments show that the transferred heat depends on three factors: (1) The change in temperature, (2) the mass of the system, and (3) the substance and phase of the substance.