Answer:
The correct option is;
C. 40 N
Explanation:
Given that the rock is on the ground, we have;
The weight of the rock, [tex]F_W[/tex] = 40 N ↓
From Newton's third law of motion, we have that action and reaction are equal and opposite,
Therefore, given that the weight of the rock exerts a force of 40 N on the ground, and the rock is stable and stationery on the ground, then the ground is reacting to the weight of the rock with an equal force of 40 N, acting in opposite direction to the weight of the block to balance the weight of the rock and create equilibrium such that the net force acting on the rock is zero
∑F = [tex]F_W + F_R[/tex] = 0
Where;
[tex]F_R[/tex] = The reaction of the ground
We have;
[tex]F_W[/tex] + [tex]F_R[/tex]= 40 + [tex]F_R[/tex] = 0
[tex]F_R[/tex] = 0 - 40 = -40
[tex]F_R[/tex] = -40 N ↓
∴ [tex]F_R[/tex] = 40 N ↑.
Answer:
C, 40N
Explanation:
plants have organelles called
Answer:
chloroplasts
Explanation:
Plants have chloroplasts which are plastids that contains chlorophyll and photosynthesis takes place.
The vector V is at a 72° angle and has a magnitude of 12.
Describe this vector using vector notation (Use the & and symbols.) (6 points)
Question 9
What is the angle of the vector described below? (3 points).
Please answer all questions will mark brainliest and give 5 stars
V=2x+3y
Answer:
Part 1
The vector can be expressed as follows;
r = 12, θ = 72°, ·v = (12, ∠72°), ·v ≈ 3.71·[tex]\mathbf{\hat i}[/tex] + 11.41·[tex]\mathbf{\hat j}[/tex] or
[tex]\mathbf{\cdot v}=\begin{bmatrix}3.71\\ 11.41\end{bmatrix} = \begin{pmatrix}3.71\\ 11.41 \end{pmatrix}[/tex]
Part 2
The angle of the vector is 56.31°
Explanation:
Part 1
The given parameters are;
The direction of the vector = 72°
The vector magnitude = 12
Therefore, the vector can be described in the following forms;
Polar form
1) Direct notation;
r = 12, θ = 72°
2) Ordered set
·v = (12, ∠72°)
Rectangular vector notation;
1) Unit vector notation
·v = vₓ[tex]\mathbf{\hat i}[/tex] + [tex]v_y[/tex][tex]\mathbf{\hat j}[/tex]
Where;
vₓ = 12 × cos(72) ≈ 3.71
[tex]v_y[/tex] = 12 × sin(72) ≈ 11.41
Therefore;
·v ≈ 3.71·[tex]\mathbf{\hat i}[/tex] + 11.41·[tex]\mathbf{\hat j}[/tex]
2) Matrix notation
[tex]\mathbf{\cdot v}=\begin{bmatrix}3.71\\ 11.41\end{bmatrix} = \begin{pmatrix}3.71\\ 11.41 \end{pmatrix}[/tex]
Part 2
The given vector is V = 2·x + 3·y
Therefore, the angle of the vector, θ = tan⁻¹(y/x) = tan⁻¹(3/2) ≈ 56.31°
The angle of the vector = 56.31°.
A student stands in a school hallway. A wall separates a classroom from
the student. The student in the hallway cannot see inside the classroom
but hears noises from within the classroom. Which of these best explains
why the student hears the noises but cannot see into the classroom?
Answer: sound waves are transmitted through the wall and visible light waves are reflected by the wall.
An inclined plane of length 12m is used to pull a load of 3000N to height of 3m by applying an effort of 1000N. Calculate its MA, VR and efficiency. Also, find the work done in the machine
Answer:
MA = 4
VR = 3
e = 0.75 or 75%
work = 12000 [J]
Explanation:
The mechanical advantage in an inclined plane is defined as the relationship between the length of the inclined plane and the height of the plane with respect to the ground.
MA = L/h
MA = 12/3 = 4
Now the real advantage can be calculated as the relationship between the weight of the body and the force being applied.
VR = W/F
VR = 3000/1000
VR = 3
Efficiency can be calculated as the relationship between the real mechanical advantage over the ideal mechanical advantage.
e = VR/MA
e = 3/4
e = 0.75 or 75%
The work is defined as the product of the force by the distance, therefore we have:
work = F*d
work = 1000*12
work = 12000 [J]
According to Rahul any two bricks tied together would fall faster than a single
one under the action of gravity by neglecting air resistance. Do you agree with
Rahul? Give a reason to support your answer.
Answer:
Rahul is wrong.
Explanation:
From Newton's universal law of gravitation, we know that the force of attraction between two falling body masses is directly proportional to product of masses of two bodies and has an inverse proportional relation with the square of the distance between the masses.
If the 2 masses are M1 & M2, while distance between them is d, this can be written as;
F ∝ M1•M2
And F ∝ 1/d²
We also know that the acceleration due to gravity is given as;
g = GM/r²
Where;
M is the mass of earth
r is the radius of earth
From the above 3 formulas, we can deduce that the value of the acceleration due to gravity(g) is independent of the 2 masses of the falling body as it depends on only the mass of the earth and radius of the earth.
This means that the acceleration due to gravity will be the same whether the bricks are doubled or whether it remains single.
Thus, they will fall with same velocity in each case. So Rahul is wrong.
Think about a neutral magnesium atom. Then think of a magnesium ion with a 2+ charge.
How are these two alike? same number of __________
How are they different? different number of ________
Group of answer choices:
A. protons, neutrons
B: protons, electron
C: electrons, neutrons
D: electrons, protons
what happens to the wave length and frequency of a wave as it crosses a different medium and speeds
Answer: SEE EXPLANATION!
Explanation:
When waves travel from one medium to another the frequency never changes. As waves travel into the denser medium, they slow down and wavelength decreases. Part of the wave travels faster for longer causing the wave to turn. The wave is slower but the wavelength is shorter meaning frequency remains the same.
I hope this helps you!
From Earth stars appear very dim, but in space they are quite bright. From Earth we are seeing the stars
A) absolute magnitude
B) apparent magnitude
C) available magnitude
D) absent magnitude
Answer:
B
Explanation:
a motorcycle stunt driver rides his motorcycle off a small ledge that is 8.4m high his initial velocity as he rides off the ledge is 25m/s in the horizontal direction how long does it take before he lands on the ground. answer= 1.3 s
Answer:
1.3s
Explanation:
In space, rockets move by shooting air backwards. What moves faster the air or the ship?
Answer:
Its being pushed.
Explanation:
There is no air but its being pushed by the flames coming from the rocket.
What is the acceleration of a 349 kg object that moved with a force of 750 N?
Answer:
The answer is 2.15 m/s²Explanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula
[tex]a = \frac{f}{m} \\ [/tex]
where
f is the force
m is the mass
From the question we have
[tex]a = \frac{750}{349} \\ = 2.14899713...[/tex]
We have the final answer as
2.15 m/s²Hope this helps you
HURRY PLEASE!!
The particles of solids are packed together tightly, so sound waves travel faster through solids than through liquids or gases. How do light waves differ from sound waves?
A. Light waves require a medium and travel fastest through liquids
B. Light waves require a medium, but travel fastest through a vacuum
C. Light waves do not require a medium, but travel fastest through solids
D.
Light waves do not require a medium and travel fastest when in a vacuum
Answer:
Hope it help you
Stayhomestaysafe
Plz mark my answer brainliest✍️✍️
Explanation:
Sound travels fastest through solids. This is because molecules in a solid medium are much closer together than those in a liquid or gas, allowing sound waves to travel more quickly through it. In fact, sound waves travel over 17 times faster through steel than through air.
Option b
REAL NAME - SHRESTH DUBEY
19. The particles in an object move very quickly and are spread apart. Then they move slower and get slower and get closer together but do not form regular and organized patterns. What change of state occured? How do you know?
Answer:
The transformation went from a gas to a solid which is a Deposition
Explanation:
Deposition is the phase transition in which gas transforms into solid without passing through the liquid phase. Deposition is a thermodynamic process. The reverse of deposition is sublimation and hence sometimes deposition is called desublimation.
The change of state that occurred was that the object went from gas to solid in a process of Deposition.
The properties of gas and solid:
Particles in gas move very quickly which leads to them being spread apart Particles in solids are quite slow and so are close togetherBased on the properties of the object before and after the change, we can infer that the object went from gas directly to solid. This process is called a deposition.
In conclusion, a deposition occurred with gas changing directly to solid.
Find out more at https://brainly.com/question/24651908.
The modern periodic table is organized by:
atomic number
atomic mass
chemical name
chemical symbol
Can you please help me it’s due at 11:59 please
Answer:
1 is summer, 2 is most likely winter,3 is most likely summer, and 4 is fall
Explanation:
Explain how the Sun's gravitational force affects Earth even though the Sun is 93 million miles away.
Answer:
Perfect distance away makes it suitable for life
Explanation:
The Sun's gravitational pull helps to control tides on earth and also to keep the earth in a curvilinear motion.
What is gravity?Gravity, or gravitation, is a natural phenomenon in which all entities with mass or energy are drawn to one another, including planets, stars, galaxies, and even light.
The gravitational pull of the sun continuously pulls the earth towards it, although because of the fast movement of the earth we never reach towards the sun instead we revolve around it.
Despite the fact that the sun's gravitational pull is neutralised by the movement of the earth in a curve, there is still some gravitational pull that exists which helps to control the tides on earth.
Thus, the Sun's gravitational pull helps to control tides on earth and also to keep the earth in a curvilinear motion.
Learn more about Gravity:
https://brainly.com/question/4014727
PLS HELP, WILL MARK BRAINLIEST!!!
A bowling ball has a mass of 5kg and weight of 49 Newtons on Earth. Astronauts take it on a journey to the moon, Phobos (a moon of Mars) and Jupiter and measure the bowling ball’s weight. Put the locations in order from least weight to most weight for the bowling ball.
(1 Point)
Earth
Jupiter
The Moon
Phobos
Answer:the moon, earth, phobos,and jupiter
Explanation:i hope im right
1. A car is traveling at 36 m/s hits a tree and comes to rest in 0.05 seconds.
a. What is the acceleration of the car?
b. Airbags deploy in a car if the acceleration of a car exceeds -600 m/s^2 Will the airbags deploy?
Answer: a. -720m/s^2
b. Yes, airbags will deploy
Explanation:
The formula for acceleration is:
= (Final velocity - Initial velocity)/Time
Final velocity = 0m/s
Initial velocity = 36m/s
Time taken = 0.05s
= (Final velocity - Initial velocity)/Time
= (0 - 36)/0.05
= -36/0.05
= -720m/s^2.
Since it's negative, it shows that there was a deceleration.
2. Yes the airbag will deploy since the acceleration gotten is more than -600 m/s^2.
You push a desk with 245 N, but the desk doesn't move due to its friction with the ground. What is the magnitude of the friction force felt by the desk?
If the desk doesn't move, then it's not accelerating.
If it's not accelerating, then the net force on it is zero.
If the net force on it is zero, then any forces on it are balanced.
If there are only two forces on it and they're balanced, then they have equal strengths, and they point in opposite directions.
So the friction on the desk must be equal to your 245N .
Does the mean molecular speed change as much as the temperature as the water heats up?
Make a claim about the time interval between lunar phases.
I will mark as BRAINLIEST ✨
just pls help ASAP
due by 4:00pm
plss
Answer:
The Lunar month is the time period for the moon to complete ONE revolution around Earth. SIDEREAL MONTH: 27.3 days SYNODIC MONTH: 29.5 days
Help plz I’m Cunfused !!
Explanation:
look up the coordinates or if they provide you with a map use that
Answer:
find each point in and draw a straight line until they touch and whatever is there is the country
in a meter of 3 how many beats are in a measure also this is for music
Answer:
3 i think
Explanation:
hope this helps also Hiiii
Why might using the speed of light to determine the length of the meter be
more reliable than using a measured distance around Earth?
Answer:ghjkdfrtghjExplanation:
What is the formula for impulse and momentum?
Answer: p = mv
Explanation: momentum(p) is equal to mass(m) and velocity(v).
A 0.660 kg ball is dropped from rest from the top of a building and falls for 5.65 seconds. How tall was the building ?
Answer:
The height of the building is approximately 156.58 m
Explanation:
The mass of the ball dropped from rest from the building top = 0.660 kg
The time in which the ball falls, t = 5.65 seconds
The height, h, of the building is given from the following equation of motion;
h = u·t + ¹/₂·g·t²
Where;
u = The initial velocity of the ball = 0 m/s
g = The acceleration due to gravity = 9.81 m/s²
Plugging in the values, we have;
h = 0 × 5.65 + ¹/₂ × 9.81 × 5.65² ≈ 156.58 m
The height of the building, h ≈ 156.58 m.
(ii)
Calculate the amount of energy required to melt 15 kg of ice at 0 °C.
Specific latent heat of fusion of ice = 3.4 x 10J/kg.
Karen has 50 cats, Gary has 14 fewer cats than Karen and Billy has 8 times more than Gary. How many cats does Billy have?
Answer:
The answer is:
14 x 8= 1.120
Answer:
288 cats
Explanation:
K = 50
G = 50 - 14 = 36
B = 36 x 8 = 288
Billy has 288 cats.
Please let me know if I'm incorrect!
what is centripetal motion
Answer:
abhi ham logo KO madam ne Padaya nahi hai
What was the first iphone
Answer:=Phone 2G
Explanation:
Answer:
model=A1203
Explanation:
it was the first iPhone invented by apple sync