Answer:
The correct option is;
11.95
Explanation:
The given parameters are;
The height from which the rock is dropped = 700 meters
The time for the to hit the ground is given by the relation, h = u·t + 1/2·g·t²
Where;
h - The height = 700 meters
u = The initial velocity = 0
t = The time taken for the rock to cover the height, h, and hit the ground
g = The acceleration due to gravity = 9.81 m/s²
Therefore, we have by substitution,
700 = 0 × t + 1/2 × 9.81 × t²
∴ t = √(700/(1/2 × 9.81)) ≈ 11.95
The time for the rock to hit the ground, t ≈ 11.95 seconds.
The normal force of a parked car is 15,000 Newtons. The coefficient of static friction between the rubber of the tires and the asphalt of the road is 0.75. What is the maximum static friction force?
Answer:
11250 N
Explanation:
From the question given above, the following data were obtained:
Normal force (R) = 15000 N
Coefficient of static friction (μ) = 0.75
Frictional force (F) =?
Friction and normal force are related by the following equation:
F = μR
Where:
F is the frictional force.
μ is the coefficient of static friction.
R is the normal force.
With the above formula, we can calculate the frictional force acting on the car as follow:
Normal force (R) = 15000 N
Coefficient of static friction (μ) = 0.75
Frictional force (F) =?
F = μR
F = 0.75 × 15000
F = 11250 N
Therefore, the frictional force acting on the car is 11250 N
Atoms of two different elements must have different
A. Electrical charges
B. Number of neutrons
C. Atomic numbers
D. Energy levels
Explanation:
C. Atomic numbers....
Answer:
atomic numbers
Explanation:
In order for two atoms to be different, they have to have a different number of protons. Protons are represented by the atomic number. Thus, atoms of two DIFFERENT elements must have different atomic numbers.
I took the test and got 100%
Hope this helps!
30 POINTS!!!! If you increase the frequency, what happens to the velocity of the wave?
In answering this question, describe how you determined the velocity as well as the result you arrived at. Then, provide a scientific explanation for this result, based on your knowledge of waves.
Answer:
As frequency increases, wavelength decreases. Frequency and wavelength are inversely proportional. This basically means that when the wavelength is increased, the frequency decreases and vice versa.
Explanation:
A wave's velocity is independent of its intensity and equal to the product of its wavelength and frequency (number of vibrations per second) so, velocity remains constant if you increase the frequency.
What is Frequency?Frequency is defined as the no of waves that are passing from the point in respect to a given time. Frequency can be measured in Hertz. Humans, whose capacity to hear is normal, can hear between the frequency of 20 Hertz to 20000 Hertz.
In mathematical form, the frequency is the factor of one divided by the time period. The number of cycles or vibrations a body in periodic motion makes in one unit of time.
Wavelength reduces as frequency rises. The relationship between frequency and wavelength is inverse. In essence, this means that the frequency reduces as the wavelength increases and vice versa.
Frequency ∝ 1 / Wavelength
Velocity = Frequency × Wavelength
Thus, it remains constant.
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PLS HELP which ones would be made of cells? and which ones show cell walls?
Cork, Sponge, Wood, Plastic, Tree
The first question's answer depends on what you mean by "sponge". If you're talking about sea sponges, then all but plastic are made up of cells. Some sponges used for cleaning are also made of plant material but also other, non-organic materials like dyes.
Cell walls are only present in plant cells, so they would be found in cork (derived from a certain tree bark), wood, and trees. Synthetic sponges made with plant material might also contain them, but they wouldn't be made entirely of cells with walls.
From given options or choices all are made up of cells except plastic and among the other four Cork, Sponge, Wood, and tree all show cell walls except Sponge.
A cell is the basic structural unit of all living organisms and contains various cell organelles. On the base of different cell organelles or presence or absence of the certain organelles help in distinct and divide the cell type.
The major types of cells are:
Prokaryotic cellsEukaryotic cellsPlastic is not a living organism as there are no cells and is made up of polymers of hydrocarbon.
The cell wall is one of the major cellular structures that helps in identifying the type of cell organism and protects the organism from the external environment. It classifies the organism on its constituent of the cell wall.
In eukaryotic cells, animal cells have no cell wall, however, fungi cells, plant cells have a cell wall. A sponge is an animal and other cork wood, and trees are plants or plant-based products.
Thus, the sponge does not show the cell wall.
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A teacher opens a window on a cold day. Which statement explains why the room starts to feel cooler? (1 point)
0 Air moves from the areas of higher temperature to areas of lower temperature
O Cold air is moving into the room from outside.
0 The density of the air is lower on the inside than on the outside
0 The kinetic energy of the air molecules outside is higher than the kinetic energy of the air molecules inside.
Answer:
Air moves from the areas of higher temperature to areas of lower temperature.
Explanation:
this is because hotter temperatures seek out colder temps.
hope this helped!
When a teacher opens a window on a cold day. the room starts to feel cooler because air moves from the areas of higher temperature to areas of lower temperature.
What is convection of heat transfer?The transfer of heat between two bodies by currents of moving gas or fluid is known as convective heat transfer. In free convection, air or water rises and is replaced by a cooler parcel of air or water as it moves away from the hot body.
As air moves from the areas of higher temperature to areas of lower temperature, when the teacher opens a window on a cold day, the air in the room moves out side and cold air takes the position inside the room. So, it feels cooler then.
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a block weighing (Fg) 50 N is resting on a steel table (us = 0.74). The minimum force to start this block moving is what N
Answer:37
Explanation:
How much Tension force is required to pull a 1500 kg car (it is being towed) forward with an acceleration of 3 m/s^2 if the friction force on the towed car's tires is pulling backward with a force of 2500 N?
If the pull is done horizontally, then the net force on the car is
∑ F = T - f = (1500 kg) (3 m/s²)
where T is the magnitude of the tension in the towing cable, and f is the friction which points in the opposite direction. Then
T = f + (1500 kg) (3 m/s²)
T = 2500 N + 4500 N
T = 7000 N
A cannonball with a perfect horizontal velocity of 50.0 m/s flies 350 m before hitting the
ground. How much time was the cannonball in the air? Remember t d/v
05s
O 10s
35 s
7s
Answer:
7 sExplanation:
The time taken can be found by using the formula
[tex]t = \frac{d}{v} \\ [/tex]
d is the distance
v is the velocity
From the question we have
[tex]t = \frac{350}{50} = \frac{35}{5} = 7 \\ [/tex]
We have the final answer as
7 sHope this helps you
which one?? please someone quick!
Answer:
i think its second law of motion.
Explanation:
Answer:
it’s the second law
Explanation:
In zoes egg experiment which two forces are balanced to keep it from hitting the pan
Answer:
The forces of push and pull
Explanation:
In the egg drop experiment, the egg is balanced on top of a toilet paper tube and balanced on a pan. The pan itself is placed on top of a glass of water. When the experimenter uses his hands to push the pan, the force of gravity pulls the egg downwards making it move down, right into the glass of water.
So the two forces which are applied in opposite directions are;
1. The force of push applied horizontally by the hand when it pushes the pan away, and
2. The force of pull caused by gravity which makes the egg move vertically downwards.
Answer:
Forces of push and pull
State the equation that links thinking distance, braking distance and stopping distance
please help !!!!! I’ll give brainliest !
Answer:
Honestly for me it's a bit too blurry. Sorry luv.:(
Explanation:
Charges are of two kinds—negative charges and ________________ charges. __________ amounts of both kinds of charges are found in every piece of matter.
Answer: the first is positive and second is equal
Explanation:
Answer: 1. Positive
Explanation:
Because there is negative charges and positive charges
when it comes to graphs I am no genius lol
Answer:
Option B
Explanation:
Displacement = Area under the velocity-time graph
So to find the displacement of a particle from 7 to 8 seconds we take the triangle and calculate its area.
[tex]Area\ of\ a\ right\ angled\ triangle = \frac{1}{2}*(base)*(height) \\\\Area\ of\ a\ right\ angled\ triangle = \frac{1}{2}*(1)*(3) \\\\Area\ of\ a\ right\ angled\ triangle = 1.5[/tex]
So the displacement is 1.5 meters
I have an uploaded image so you can understand it better hope it helps
Which two types of waves require matter in order to travel? A. Light waves B. Sound waves C. Electromagnetic waves D. Water waves
Answer:
b & c
Explanation:
because is my choice
Coretta feels confident in her abilities, and she frequently makes contributions to her local community. Based on this information, what can you assume is true about Coretta?
A She has good emotional health.
B She makes self-esteem a priority.
C She recently improved her mental health.
D She exercises at least twice a day.
Answer:
A She has good emotional health.
Explanation:
3 Kyra and Pari are timing how long it takes for 1 g of sugar to dissolve in hot water.
Kyra records a time of 24.3 seconds. Pari records a time of 24 seconds. Whose reading
is more precise? Why?
Answer:
Kyra is more precise.
Explanation:
Kyra is more precise as she has included the exact point second it had dissolved whereas Pari just rounded it to the closest number making her write a whole number that was rounded down.
What force would be needed to increase a 450 kg object's velocity from 15 m/s to 75 m/s in 1 minute?
Answer:
450N
Explanation:
Given parameters:
Mass of object = 450kg
Initial velocity = 15m/s
Final velocity = 75m/s
Time = 1min = 60s
Unknown:
Force applied = ?
Solution:
To solve this problem, from Newton's second law of motion, we know that;
Force = mass x acceleration
Acceleration = [tex]\frac{v - u }{t}[/tex]
v is the final velocity
u is the initial velocity
t is the time taken
Now;
Force = mass x [tex]\frac{v - u }{t}[/tex]
Force = 450 x [tex]\frac{75 - 15}{60}[/tex] = 450N
PLEASE HELP ME IM TIMED
Answer:
the answer is the core
Explanation:
the core is composed of iron and nickel
On a sunny summer day, why does a white car with a light-colored interior stay cooler than a black car with a dark-colored interior?
Solar radiation reflects off the lighter colours, away from the car, thus keeping the car cool
Solar radiation is absorbed into the lighter colours, keeping the car cool
Solar radiation is absorbed into the darker colours, keeping the car cool
Solar radiation reflects off the darker colours, away from the car, thus keeping the car cool
Answer: Solar radiation reflects off the lighter colours, away from the car, thus keeping the car cool
Explanation: This is because lighter colors reflect a good amount of radiation while darker colors absorb it. Just like, Antarctica hasn't completely melted because it reflects a lot of the heat that is acting upon it. Or, you notice that you get hotter when you wear a black shirt opposed to a white one.
a cannon launches a 3.0 kg pumpkin with 110J of kinetic energy. what is the pumpkin’s speed?
Answer:
v = 8.56 [m/s]
Explanation:
The kinetic energy can be calculated by means of the following equation.
[tex]E_{k}=\frac{1}{2}*m*v^{2}[/tex]
where:
m = mass = 3 [kg]
v = velocity [m/s]
Ek = kinetic energy [J]
[tex]110 = \frac{1}{2} *3*(v^{2} )\\v^{2} = 220/3\\v=\sqrt{73.333}\\v=8.56[m/s][/tex]
What training principle states that you must continue to exercise to mantain fitness a. Balance
Help me please help me it’s due today
Answer:
Explanation:
A) The function of a switch is to shut the circuit down. There is a current flow of zero. Press the switch again and the circuit works.
Answer: D
B) a. This is a parallel circuit. It is the way all house wiring works.
B) b. Nothing happens. The other two bulbs continue on as before until someone presses the switch.
How much power will it take to move a 10 kg mass at an acceleration of 2 m/s² a distance of 10 meters in 5 seconds?
Answer:
100 Watts
Explanation:
These equations are needed to work out the answer:
power= work done/ time takenwork done= force* distanceforce= mass* accelerationforce: 10 kg* 2m/s= 20
work done: 20* 10m=200
power: 200/2=100
The gravitational force between two objects is
proportional to the products of the masses and
proportional to the square of the distance between them.
The complete question is;
The gravitational force between two objects is ______ proportional to the products of the masses and _______ proportional to the square of the distance between them.
Answer:
First dash is directly
Second dash is inversely
Explanation:
From Newton's law of gravitation the gravitational force is given by the equation;
F = GMm/r²
Where:
F is gravitational force
M and m are two masses representing the two objects
r is the distance between them
G = universal gravitational constant
Thus, if we are to write it in proportion format, we will have;
F ∝ Mm/r²
From this proportion relationship, we can see that the Gravitational force is directly proportional to the products of the two masses and inversely proportional to the square of the distance between them.
Answer:
DirectlyInverselyExplanation:
The gravitational force between two objects is directly proportional to the products of the masses and inversely proportional to the square of the distance between them.
define unit aland how many types of unit are there . Name them?
Answer:
7. They arethe meter (m), the kilogram (kg), the second (s), the kelvin (K), the ampere (A), the mole (mol), and the candela (cd)
Explanation:
7. They arethe meter (m), the kilogram (kg), the second (s), the kelvin (K), the ampere (A), the mole (mol), and the candela (cd)
What is the velocity of the rock after 3.00 seconds (the rock is falling from a cliff)
Answer:
29.4 m/s
Explanation:
Using the formula: V=Vi + g.t
where V: final velocity, this is what you want.
Vi: initial velocity, equals to zero as it is falling from rest.
g: acceleration due to gravity = 9.8
t: time, which equals 3 sec.
A 3900 kg truck is moving at 6.0 m/s what is the kinetic energy
Answer:
70200J
Explanation:
k.E = 1/2mv^2
K.E = 1/2(3900)(6)^2
Who believe in astrology?
Why is it possible to see yourself in an object that reflects light, but not in one that scatters light?