Answer:
Explanation:
The oly way we can figure this out is if the boy is pulling the sled at a constant velocity. If not, we need a value for acceleration, and you don't have that here. If the boy is pulling the sled at a constant velocity, then the value for acceleration is 0, making this a really simple problem. I'm going with that, since there is no way to answer you otherwise. If velocity is not constant, please either repost the question or put it in the notes section under the question as it stands. If acceleration is 0, then
F - f = ma becomes
F - f = m(0) which is
F - f = 0 and
F = f which says that the applied force is the same as the frictional force. We need then to find the frictional force, which has an equation of
f = μ[tex]F_n[/tex] where normal force is the same as the weight of the 2 girls. We will find that, then:
Each girl's mass is different so the normal force/weight equation is
w = (30.0)(9.8) + (40.0)(9.8) to get
w = 290 + 390 and
w = 680. Plug that into the frictional force equation:
f = (.120)(680) so
f = 82N
A block of aluminium of density 7900 kg/m3 has a volume of 250 cm. Find the
mass of the block.
Answer:
mass of block=2.7 gm
Explanation:
concept: Density=mass/volume
given:ρ=2700 kg/m^3 and v=250 cm^3 (in cm^3 not in m^3)
=> v= convert cm^3 to m^3
there fore= 1 cm^3=1 cm*1 cm*1 cm
i.e 1 cm^3=1/100*1/00*1/100 m^3 => 1 cm^3=1/1000000 m^3
ρ=m/v
=>mass=ρ*volume
=>mass=2700*1/10^-6
=>mass=2.7*10^-3 kg =>2.7 gm
Which of these materials is an insulator?
Answer:
Plastic, rubber, wood, and ceramics are good insulators. These are often used to make kitchen utensils, such as saucepan handles, to stop heat from flowing up to burn the cook's hand. Plastic coating is also used to cover most electrical wires in appliances. Air is also a good insulator of heat.
Can you tell from an FBD if an object is moving or not? Explain your response.
Answer:
Yes it is possible to tell if an object is moving or not using a FBD based on Newton's Laws of Motion
Explanation:
A Free Body Diagram is the representation of an object in a diagram that shows (all) the vector of the forces that act on the object
When the sum of all the force vectors acting on the body give a resultant force the object will move in the direction of the force according to Newton's First Law of motion, which states that an object will continue in its rest state or continue its uniform motion on a straight path unless a force acts on the object
The net force, 'F', can be represented according to Newton's Second Law of motion which is F = m·a, where 'a' represents the acceleration (rate of change in velocity) of the object as the object begins to move from rest
Therefore;
From a FBD it is possible to tell if an object is moving or not.
EASY BRAINLIEST PLEASE HELP!!
-if you answer correctly ill give you brainliest which will give you 100pts-
(if you put links or don't answer accordingly im reporting your account)
Answer:
look at the picture i have sent
Answer:
solution given:
frequency[f]=215.0Hz
velocity[V]=x
wave length=2.4m
we have
wave length=[tex] \frac{V}{f} [/tex]
2.4m=[tex] \frac{x}{215} [/tex]
2.4×215=[tex] \frac{x}{} [/tex]
x=516 m/s
velocity=speed =516m/s
A defibrillator is used during a heart attack to restore the heart to its normal beating pattern. A defibrillator passes 18 A of current: through the torso of person in 2.0 ms- (a) How much charge moves during this time
Answer:
q = 0.036 C
Explanation:
Given that,
Current passes through a defibrillator, I = 18 A
Time, t = 2 ms
We need to find the charge moved during this time. We know that,
Electric current = charge/time
[tex]q=It[/tex]
Put all the values,
[tex]q=18\times 0.002\\\\q=0.036\ C[/tex]
So, 0.036 C of charge moves during this time.
What is the density of the metal
Answer:
Density is the mass per unit volume of that metal.
Explanation:
[tex]density = \frac{mass}{volume} [/tex]
A marble block of mass 2 kg lying on ice when given a velocity of 6 m/s is stopped by a friction in 10s then what is the coefficient of friction?
Answer:
[tex]\mu=0.06[/tex]
Explanation:
Given that,
Mass of a block, m = 2 kg
Velocity of the block, v = 6 m/s
It stopped in 10 s
We need to find the coefficient of friction.
The frictional force is balanced by the opposing force such that,
[tex]\mu mg=ma\\\\\mu=\dfrac{a}{g}[/tex]
Where
a is acceleration, a = 6/10 = 0.6 m/s
So,
[tex]\mu=\dfrac{0.6}{10}\\\\\mu=0.06[/tex]
So, the coefficient of friction is equal to 0.06.
A cell of emf 18v has an internal resistance of 3ohm . the terminal p.d of the battery becomes 15v when connected by a wire. find the resistance of the wire.
Answer:
Resistance = 15 Ohms
Explanation:
Given the following data;
Emf voltage = 18 V
Internal resistance = 3 Ohms
Potential difference = 15V
To find the resistance of the wire;
First of all, we would determine the current flowing through the wire.
Mathematically, the terminal potential difference is given by the formula;
V = E - IR
Where;
V is the terminal potential difference.
E is the electromotive force (emf).
I is the current.
R is the internal resistance.
15 = 18 - I*3
15 = 18 - 3I
3I = 18 - 15
3I = 3
I = 1 Amperes
Next, we find the resistance of the wire;
Voltage = current * resistance
Substituting into the formula, we have;
15 = 1 * resistance
Resistance = 15/1
Resistance = 15 Ohms
What is the speed of the curiosity rover if it travels 10,000 ft. In 25 hours
Answer:
it is going 1.894miles in 25 hours so it travels 0.07576 miles per hour
Which statement correctly describes mass-energy equivalence?
A. All energy in the universe will be converted to an equivalent amount of mass.
B. Mass can decrease in nuclear changes without the production of energy.
C. All energy in the universe is a result of mass being converted into energy.
D. A large amount of mass is equivalent to a small amount of energy.
C is the answer on edge 2021
Answer:
C. All energy in the universe is a result of mass being converted into energy.
Explanation:
Answer:
C
Explanation:
edgeee
. idea that the ears receive slightly different inputs when the sound source is located to one side or the other. b. location of the sound in space. c. difference in time between a sound arriving at one ear versus the other. d. angle of a sound source on the horizontal plane relative to a point in the center of the head between the ears. e. distance between the sound and the ears.
Answer: hello your question is incomplete below is the missing part
What is Azimuth ?
answer : angle of a sound source on the horizontal plane relative to a point in the center of the head between the ears ( D )
Explanation:
Azimuth is the described as angle of a sound source ( between the North ) and it is measured in a clockwise direction in relation to the observer ( Human ear )
Hence the option that fits in is : angle of a sound source on the horizontal plane relative to a point in the center of the head between the ears
12. Which of the following is true of an electrolyte?
A. It is a component of a cell, but not a battery.
B. It is a component of a wet cell but not a dry cell.
C. It is a component of a dry cell but not a wet cell.
D. It is a component of both a wet cell and a dry cell.
Answer:
A
Explanation:
It’s a because a electrolyte reproduces
Examples of usage of fluid pressure in real life
Answer:
Syringes are used to take blood for blood tests. The pressure of the liquid (blood) forces the liquid to move into the syringe when its plunger is withdrawn. When air is sucked out of a drinking straw, the air pressure inside if decreases and the atmospheric pressure outside forces the liquid to go inside the straw.
please mark as brainliest
Answer: The area of the edge of a knife’s blade is very small
Syringes are used to take blood for blood tests.
When air is sucked out of a drinking straw, the air pressure inside if decreases and the atmospheric pressure outside forces the liquid to go inside the straw.
Skis have a large area to reduce the pressure on the snow.
3.) What allows elements larger than iron to form in the universe?
a. Black holes
b. Small star fusion
c. Star explosions
d. Star fission
Answer:
c) star explosions.....
If V is the original volume, V' is the new volume, T is the original Kelvin temperature, and T' is the new Kelvin temperature, how is Charles's law expressed mathematically
Answer:
[tex] \frac{V}{T} = \frac{V'}{T'}[/tex]
Explanation:
Given the following data;
Original volume = V
New volume = V'
Original temperature = T
New temperature = T'
To write an expression for Charles's law;
Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.
Mathematically, Charles law is given by the formula;
[tex] \frac {V}{T} = K[/tex]
[tex] \frac{V}{T} = \frac{V'}{T'}[/tex]
Jasmine took the following notes in science class:
Which is the best title for these notes?
Answer:
Definition of a scientific theory.
Answer:
theories on edge
Explanation:
Describe succinctly the relationship between how far a galaxy is from us (its distance), versus how fast it is moving.
Answer:
Distance is directly proportional to the velocity
Explanation:
In 1929, Edwin Hubble's wrote an article that talked about relationship between the distance and recession speed/velocity of galaxies which led to what is known as the Hubble Law. This law states that galaxies are moving away from the earth at velocities proportional to their distances.
Thus is written as;
v = H_o•d
Where;
v is velocity
d is distance
H_o is Hubble's constant rate of cosmic expansion.
He came to this conclusion by generating a graph known as Hubble's classic graph which was a graph of observed velocity vs distance for nearby galaxies.
the teacher said to the students you can go home change the folowing sentence into indirect
Explanation:
The teacher said to the students you can go home.
Into indirect speech
The teacher told the students that they could go home.
Hope it will help :)❤
Four 29-ohm resistors are connected in series to an ideal 10-volt battery. What is the equivalent resistance of the circuit?
Answer:
Equivalent resistance of the circuit is 116 ohm.
Explanation:
Finding the equivalent resistance of the circuit. Since, 29 ohm resistors are connected in series, so
→ Equivalent resistance = R_1 + R_2 + R_3 + R_4
→ Equivalent resistance = (29 + 29 + 29 + 29) ohm
→ Equivalent resistance = 116 ohmWhat statements are true???
Answer:
Explanation:
opposite charges attract
same charges repel
neutral charges don't attract or repel
Dish-shaped reflectors are used to steer microwaves in order to establish communications links between nearby buildings. Those reflectors are often made from metal mesh. Why don't they have to be made from solid metal sheets
A "screen" or even just a set of parallel bars are highly reflective to electromagnetic waves as long as the open spaces are small compared to the wavelengths.
"Grid" dishes work fine ... with less weight and less wind resistance ... for frequencies below about 3 GHz. (Wavelengths of at least 10 cm.)
(I even worked on a microwave system in South America where huge grid dishes were used on a 90-mile link.)
If energy is going into a system, but not being converted into kinetic energy, it will be converted into potential energy. This will be represented by a __________________ on a heating curve, which occur at the __________________ and ____________________.
Answer:
1. Plateau where the temperature stays constant
2. Melting
3. Boiling points of the substance
Explanation:
The relationship between kinetic energy and temperature is given as follows;
[tex]\overline E = \dfrac{3}{2} \times \dfrac{R}{N_A} \times T[/tex]
Where;
[tex]\overline E[/tex] = The average kinetic energy of the atom
R = The universal gas constant
[tex]N_A[/tex] = Avogadro's number
T = The temperature in Kelvin
Therefore, the kinetic energy increases as the temperature increases, however when the energy is not being converted into kinetic energy, the energy is stored as internal potential energy in the melted or evaporated state of the substance
Therefore, we have;
If energy is going into a system, but not being converted into kinetic energy, it will be converted into potential energy. This will be represented by a 1. plateau where the temperature stays constant on a heating curve, which occur at the 2. melting and 3. boiling points of the substance.
A 3.00 x 10-2-kg block is resting on a horizontal frictionless surface and is attached to a horizontal spring whose spring constant is 124 N/m. The block is shoved parallel to the spring axis and is given an initial speed of 11.9 m/s, while the spring is initially unstrained. What is the amplitude of the resulting simple harmonic motion
Answer:
[tex]A=0.185m[/tex]
Explanation:
From the question we are told that
Mass of Block [tex]M=3*10^-2kg[/tex]
Spring constant [tex]\mu=124 N/m[/tex]
Initial Speed [tex]V_1=11.9m/s[/tex]
Generally the equation for Kinetic Energy is mathematically given by
[tex]K.E=1/2 mv^2[/tex]
Therefore
[tex]K.E_1=1/2*0.03*11.9^2[/tex]
[tex]K.E_1=2.12J[/tex]
Where
[tex]Initial K.E_1=Final K.E[/tex]
Generally the equation for Final Energy stored is mathematically given by
[tex]K.E_2=0.5\mu a^2[/tex]
Therefore
[tex]K.E_1=K.E_2[/tex]
[tex]0.5\mu A^2=2.12J[/tex]
[tex]A=\sqrt{\frac{2.12}{0.5*124}}[/tex]
[tex]A=0.185m[/tex]
Therefore the amplitude of the resulting simple harmonic motion is
[tex]A=0.185m[/tex]
calculate the work done by 2N force directed at 30 degree to the vertical to move a 500g box a horizontal distance of 400 cm across a rough floor at constant speed of 0.5 m per second
Answer:
there is no picture :o?
Explanation:
:oo
Which quantities are scalars?
Answer:
Speed and distance are examples of scalar quantities.
Answer:
d
Explanation:
easy hope it helps#CARRYONLEARNING!How much heat is required to raise the temperature of 100 g of water from 5 degree celsius to 90 degree celsius?
Explanation:
1-How many moles of NazCOs are in 10.0 ml of a 2.0 M solution?
2-How many moles of NaCl are contained in 100.0 ml of a 0.20 M solution?
3- What weight (in grams) of H2SO4 would be needed to make 750.0 ml of
2.00 M solution?
4-What volume (in ml) of 18.0 M H2SO4 is needed to contain 2.45 g H2S04?
What would be the force required to accelerate an object that weighs 35 N up at a rate of .60 m/s^2?
Answer: [tex]2.14\ N[/tex]
Explanation:
Given
Force required to accelerate the object at the rate of [tex]0.6\ m/s^2[/tex]
The weight of the object is [tex]W=35\ N[/tex]
Mass of the object can be identified by dividing the weight by acceleration due to gravity
[tex]\Rightarrow m=\dfrac{W}{g}\\\\\Rightarrow m=\dfrac{35}{9.8}\\\\\Rightarrow m=3.57\ kg[/tex]
[tex]\therefore \text{Force F=}m\times a\\\Rightarrow F=3.57\times 0.6\\\Rightarrow F=2.14\ N[/tex]
If all your cells were the same, could you still do everything you do now?
Explain.
Answer:
No, you couldn't function the same as you do now.
Explanation:
This is because each cell follows individual tasks, and makes up specific parts of a body. For example, if all of your cells were those of an eye, you would be missing the components of arms, legs, etc.
Answer: No
Explanation: If all the cells of our body were of the same size, shape and volume, then they would all perform the same function and the multitude of other important functions cannot be carried out, without which human life itself would not be possible.
What do you think is the factor that causes projectile path to bend?
The movement of an object in a curved path toward the ground due to the application of a horizontal force and the downward force of gravity is projectile motion. The gravity is the factor that leads to bend of projectile path.
What is gravity?Gravity is the universal force of attraction that holds all matter together. It is by far the weakest known natural force and thus has no influence on the internal properties of everyday matter.
A projectile is an object whose main force is gravity. Because gravity is a downward force, it causes a projectile to accelerate downward.
Thus, the factor that causes projectile path to bend is gravity.
For more details regarding gravity, visit:
https://brainly.com/question/13810323
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Which of the following has greater kinetic energy?
(a). A 10 g meteor hurtling (Moving at greater speed) through the Earth’s atmosphere at 5.0 km s−1. (b). A 65 kg jogger running at 5.0 m s−1.
please help me
Answer:
A
Explanation: