Answer:
2.398
Explanation:
In order to solve this problem we are required to use the following information and the question expects us to give depth at which theask is seen.
Dn = D x nobservation/n object
This is the formula for apparent depth
Depth = 3.19
The index of refraction for water is 1.33
3.19x1/1.33
= 3.19/1.33
= 2.398m
the person see his dive mask at
2.398m (apparent depth in meters
9)A skier starts from rest from the top of a 40 m high slope which makes 40 degrees with the ground. Coefficient of friction is 0.1 What is the velocity of the skier at the bottom of the ramp?
Answer:
The velocity of the skier at the bottom of the ramp is approximately 26.288 meters per second.
Explanation:
We can determine the final velocity of the skier at the bottom of the ramp by Principle of Energy Conservation and Work-Energy Theorem, whose model is:
[tex]U_{g,1}+K_{1} = U_{g,2}+K_{2}+W_{disp}[/tex] (1)
Where:
[tex]U_{g,1}[/tex], [tex]U_{g,2}[/tex] - Initial and final gravitational potential energy, measured in joules.
[tex]K_{1}[/tex], [tex]K_{2}[/tex] - Initial and final translational kinetic energy, measured in joules.
[tex]W_{disp}[/tex] - Work dissipated by friction, measured in joules.
By definitions of gravitational potential and translational kinetic energy and work, we expand and simplify the model:
[tex]m\cdot g \cdot (z_{1}-z_{2})+\frac{1}{2}\cdot m \cdot (v_{1}^{2}-v_{2}^{2}) =\mu_{k}\cdot N\cdot \Delta s[/tex] (2)
Where:
[tex]m[/tex] - Mass, measured in kilograms.
[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.
[tex]z_{1}[/tex], [tex]z_{2}[/tex] - Initial and final heights of the skier, measured in meters.
[tex]N[/tex] - Normal force from the incline on the skier, measured in newtons.
[tex]\Delta s[/tex] - Distance covered by the skier, measured in meters.
[tex]\mu_{k}[/tex] - Kinetic coefficient of friction, dimensionless.
The normal force exerted on the skier and the covered distance are, respectively:
[tex]N = m\cdot g\cdot \cos \theta[/tex] (3)
[tex]\Delta s = \frac{z_{1}-z_{2}}{\sin \theta}[/tex] (4)
Where [tex]\theta[/tex] is the angle of the incline above the horizontal, measured in sexagesimal degrees.
By applying (3) and (4) in (2), we get that:
[tex]m\cdot g \cdot (z_{1}-z_{2})+\frac{1}{2}\cdot m\cdot (v_{1}^{2}-v_{2}^{2}) = \mu_{k}\cdot m\cdot g \cdot \cos \theta \cdot \left(\frac{z_{1}-z_{2}}{\sin \theta} \right)[/tex]
[tex]g\cdot (z_{1}-z_{2}) +\frac{1}{2}\cdot (v_{1}^{2}-v_{2}^{2})= \mu_{k}\cdot g \cdot \left(\frac{z_{1}-z_{2}}{\tan \theta} \right)[/tex] (5)
Then, we clear the velocity of the skier at the bottom of the ramp is: ([tex]v_{1} = 0\,\frac{m}{s}[/tex], [tex]\mu_{k} = 0.1[/tex], [tex]\theta = 40^{\circ}[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], [tex]z_{1}-z_{2} = 40\,m[/tex])
[tex]\left[\frac{\mu_{k}}{\tan \theta}-1 \right]\cdot g\cdot (z_{1}-z_{2}) = \frac{1}{2}\cdot (v_{1}^{2}-v_{2}^{2})[/tex]
[tex]2\cdot \left[\frac{\mu_{k}}{\tan \theta}-1 \right]\cdot g\cdot (z_{1}-z_{2}) = v_{1}^{2}-v_{2}^{2}[/tex]
[tex]v_{2} = \sqrt{v_{1}^{2}-2\cdot \left[\frac{\mu_{k}}{\tan \theta}-1 \right]\cdot g\cdot (z_{1}-z_{2})}[/tex] (6)
[tex]v_{2} = \sqrt{\left(0\,\frac{m}{s} \right)^{2}-2\cdot \left(\frac{0.1}{\tan 40^{\circ}} -1\right)\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot (40\,m)}[/tex]
[tex]v_{2} \approx 26.288\,\frac{m}{s}[/tex]
The velocity of the skier at the bottom of the ramp is approximately 26.288 meters per second.
Please answer my question
Answer:
Answer is (b) Mercury, venus and Mars.
Explanation:
i think b is correct!!
;-) :-) :-) :-)
An electron and a proton have charges of an equal magnitude but opposite sign of 1.60 x 10^-19 C. If the electron and proton in a hydrogen atom are separated by a distance of 4.20 x10^-11 m, what are the magnitude and direction of the electrostatic force exerted on the electron by the proton?
Answer:
i. F = 1.3 x [tex]10^{-7}[/tex] N
ii. The direction of the force of attraction exerted by the proton on the electron is towards the itself (i.e a pull).
Explanation:
Since the given charges are opposite, then the force of attraction is experienced. The force of attraction between the two charges can be determined by:
F = [tex]\frac{kq_{1} q_{2} }{d^{2} }[/tex]
where F is the force, k is the constant, [tex]q_{1}[/tex] is the charge of the electron, [tex]q_{2}[/tex] is the charge on the proton, and d is the distance between them.
So that; k = 9.0 x [tex]10^{9}[/tex] N[tex]m^{2}[/tex][tex]C^{-2}[/tex] , [tex]q_{1}[/tex] = 1.6 x [tex]10^{-19}[/tex] C, [tex]q_{2}[/tex] = 1.6 x
Thus,
F = [tex]\frac{9.0*10^{9}*1.6*10^{-19}*1.6*10^{-19} }{(4.2*10^{-11}) ^{2} }[/tex]
= [tex]\frac{2.304*10^{-28} }{1.764*10^{-21} }[/tex]
= 1.3061 x [tex]10^{-7}[/tex]
F = 1.3 x [tex]10^{-7}[/tex] N
The force between the charges is 1.3 x [tex]10^{-7}[/tex] N.
ii. The direction of the force of attraction exerted by the proton on the electron is towards the itself.
Consider a person standing in an elevator that is moving at a constant velocity down. The upward normal force N exerted by the elevator floor on the person is Select one: a. smaller than the downward force of gravity on the person. b. identical to the downward force of gravity on the person. c. larger than the downward force of gravity on the person.
Answer:
b. identical to the downward force of gravity on the person.
Explanation:
For an object in an elevator,
F = mg - ma (g > a)
But since the velocity is uniform, a = 0.
Then,
F = mg - 0
F = mg
This is the actual weight of the object.
The object does not feel weightless, so that its actual weight can be measured during the downward motion of the elevator with uniform velocity.
Thus, the upward normal force, N, exerted by the elevator floor on the person is identical to the downward force of gravity on the person.
If 10 calories of energy are added to 2 grams of ice at -30° C, calculate the final temperature of the ice. (Notice that the specific heat of ice is different from that of water.)
-30° C
40° C
-20° C
30° C
Answer:
-20°C
Explanation:
The specific heat capacity of ice using the cgs system is 0.5cal/g°C
The enthalpy change is calculated as follows
ΔH=MC∅ where M represents mass C represents specific heat and ∅ represents the temperature change.
10cal = 2g×0.5cal/g°C×∅
∅=10cal/(2g×0.5cal/g°C)
∅=10°C
Final temperature= -30°C+ 10°C= -20°C
A Long Jumber leaves the ground at on
a bouche horizontal al speed ilms.
How far does he jume in the horizontal direction ?
Answer:
horizontal velocity vh = 6*cos(30°) = 6*(√3)/2 = 3√3 m/s
initial vertical velocity vv = 6*sin(30°) = 6/2 = 3m/s
Using s = ut + at2/2 for change in vertical distance in time t, with acceleration a (-9.8m/s2) and initial velocity u (vv = 3m/s) we have
0 = 3*t - 9.8*t2/2 or t = 6/9.8 s (ignoring the t = 0 solution, which just represents staying still!).
The horizontal distance in time t is vh*t or 3√3*6/9.8 m
Explanation:
In contact forces, _____.
A.) objects do not touch each other
B.) objects must touch each other
C.) more work is done than in other forces
Answer:
B is the best answer for this
What is the current in the wire now?
Answer:
220v
Explanation:
Sorry, the question is incomplete
Answer:
on the potential difference applied and on the resistance of the wire.
Explanation:
Ohms law state that the current through a conductor between two points is directly proportional to the potential difference across the two points. Imtroducing the comstant of proportionality, the resistance, one arrives at the usual athematical equation that describes this relationship: I = V/R.
A scientist decides to replicate an experiment completed by another scientist. Which statement describes something that would not affect the results of the replicated experiment
Hi, you've asked an incomplete question. However, I provided some explanation about the replication process that scientists do.
Explanation:
Replication in research involves carefully repeating an original experiment to see whether the same result would be arrived at as in previous research experiments.
For most scientists today, in other to avoid anything that would erroneously affect the results of the replicated experiment they usually follow the same procedures as carried by the previous researchers.
PLEASEEE HELPPPPP does anyone know these answers?
Answer:
oof ok
Explanation:
Thank you :)
If force remains the same, and the mass of an object increases, what happens to the acceleration?
Answer:
Decreases
Explanation:
Force= mass * acceleration
If the mass increases but force stays the same then the acceleration would have to decrease to maintain the same force
2. Which bicyclist was traveling the fastest at the end of the race?
Answer:
This question is incomplete
Explanation:
This question is incomplete. However, to determine the bicyclist that traveled the fastest at the end of the race, the speed of the bicyclists at the end of the race will determine this (not the bicyclist that came first nor there overall speed). The speed of the bicyclist at the end of the race can be determined by using the formula below
s = d ÷ t
Where s is the speed of each bicyclist at the end of the race
d is the specific distance covered by the bicyclist at the end of the race
t is the time taken for the bicyclist to complete that distance
It should be noted that to get an accurate result, the distance covered at the end of the race must be the same for all the bicyclists.
If the velocity of a car changes from 0 meters per second (m/s) to 100 m/s in 10 seconds, what is the acceleration over that 10 second period?
Answer:
10m/s²
Explanation:
Given parameters:
Initial velocity = 0m/s
Final velocity = 100m/s
Time taken = 10s
Unknown:
Acceleration = ?
Solution:
Acceleration is the rate of change of velocity with time.
A = [tex]\frac{v - u}{t}[/tex]
v = final velocity
u = initial velocity
t = time taken
So, insert the parameters and solve;
A = [tex]\frac{100 - 0}{10}[/tex] = 10m/s²
true or false the melting of ice cubes is a exothermic reaction
[tex]\huge\boxed{False}[/tex]
_____________________________________ENDOTHERMIC REACTIONS:Endothermic Reaction are those reactions in which the reactants absorb the energy from their surrounding and forms the product.
_____________________________________How to know endothermic reaction?Those changes in which a substance goes from More-ordered state to less-oredered state are endothermic. Where they change from less ordered to more ordered is exothermic.
More ordered means that the movement of vibration of the particles of the substance is less and the are more close to each other. More to less ordered state is given as,
Solid>Liquid>Gas.
_____________________________________Question:In the question it asks about the melting of the ice cube. Ice cube is a solid, and when it will melt, it will change into the liquid water. As we know that, Solid is more ordered and Liquid is less ordered, and The change from more-ordered to less-ordered is endothermic thus the answer is ENDOTHERMIC.
_____________________________________Best Regards,'Borz'20- A gram of distilled water at 4° C:
(a) will increase slightly in weight when heated to 6 C
(b) will decrease slightly in weight when heated to 6 C
(C) will increase slightly in volume when heated to 6 C
(d) will decrease slightly in volume when heated to 6 C
(e) will not change in either volume or weight
Answer:
D. will decrease slightly in volume when heated to 6° C
Explanation:
A gram of distilled water at 4° C will increase slightly in volume when heated to 6 C. Hence option C is correct.
What is Water ?Water has the chemical formula H2O, making it an inorganic substance. It is the primary chemical component of the Earth's hydrosphere and the fluids of all known living things (in which it serves as a solvent[1]). It is translucent, flavourless, odourless, and almost colourless. In spite of not supplying food, energy, or organic micronutrients, it is essential for all known forms of life. Its molecules are made up of two hydrogen atoms joined by covalent bonds and have the chemical formula H2O. The angle at which the hydrogen atoms are joined to the oxygen atom is 104.45°.[2] The liquid condition of H2O at normal pressure and temperature is known as "water" as well.
Water occurs because the environment on Earth is pretty near to the triple point of water.
To know more about Water :
https://brainly.com/question/28465561
#SPJ2.
A solid spherical ball and a hollow spherical ball made out of the same material are released from rest at the top of a ramp. They roll down the ramp without slipping to the bottom. On what quantities does the speed of each ball at the bottom of the ramp depend?A. Radius of the ball.B. Distribution of mass within the ball.C. Mass of the ball.D. Height of the ramp.
Answer:
D. Height of the ramp.
Explanation:
The solid spherical ball is expected to have more mass than that of the hollow spherical ball. And the speed of both balls would be influenced by the gravitational force as they roll down the ramp. Thus, the masses would move at different speed.
At the bottom of the ramp, the speed of the balls can be varied by varying the height of the ramp. So that the speed of both balls depend on the height of the ramp. As the height of the ramp increases, consequently, the speed of the balls increases. And if the height of the ramp decreases, the speed of the balls decreases consequently.
During the stretching routine who used the medicine ball for support.
The guy
The guy
The Girl
The Girl
Both people used a ball for support
Both people used a ball for support
No one used it
No one used it
A large pizza is cut into 8 even slices. A person orders 4 large pizzas from a restaurant. How many total slices of pizza did the person order?
Answer:
32 slicesExplanation:
Step one:
given data
we are told that 1 large pizza can be cut into 8 even slices
Required
we want to find how many slices are there in 4 large pizzas
Step two:
so if 1 pizza has 8 slices
4 pizza will have x
cross multiply we have
x= 8*4
x=32 slices
A 4.8-g particle is moving toward a stationary 7.4-g particle at 3.0 m/s. What percentage of the original kinetic energy is convertible to internal energy?
Answer:
60.185 percent of the original kinetic energy is convertible to internal energy.
Explanation:
Let suppose that collision between both particles is entirely inellastic. If there is no external forces exerted on any of the particles, then we can apply the Principle of Linear Momentum Conservation. That is:
[tex]m_{A}\cdot v_{A,o} + m_{B}\cdot v_{B,o} = (m_{A}+m_{B})\cdot v[/tex]
[tex]v = \frac{m_{A}\cdot v_{A,o}+v_{B}\cdot v_{B,o}}{m_{A}+m_{B}}[/tex] (1)
Where:
[tex]m_{A}[/tex] - Mass of the 4.8-g particle, measured in kilograms.
[tex]m_{B}[/tex] - Mass of the 7.4-g particle, measured in kilograms.
[tex]v_{A,o}[/tex] - Initial speed of the 4.8-g particle, measured in meters per second.
[tex]v_{B,o}[/tex] - Initial speed of the 7.4-g particle, measured in meters per second.
[tex]v[/tex] - Final speed of the collided particles, measured in meters per second.
If we know that [tex]m_{A} = 4.8\times 10^{-3}\,kg[/tex], [tex]m_{B} = 7.4\times 10^{-3}\,kg[/tex], [tex]v_{A,o} = 3\,\frac{m}{s}[/tex] and [tex]v_{B,o} = 0\,\frac{m}{s}[/tex], then the final speed of the system is:
[tex]v = \frac{(4.8\times 10^{-3}\,kg)\cdot \left(3\,\frac{m}{s} \right)+(7.4\times 10^{-3}\,kg)\cdot \left(0\,\frac{m}{s} \right)}{4.8\times 10^{-3}\,kg+7.4\times 10^{-3}\,kg}[/tex]
[tex]v = 1.180\,\frac{m}{s}[/tex]
During the collision part of the initial energy is dissipated in the form of heat, which is related to the internal energy ([tex]\Delta U[/tex]), measured in joules. According to the Principle of Energy Conservation, we have the following model:
[tex]\Delta U = K_{A}+K_{B}-K[/tex] (2)
Where:
[tex]K_{A}[/tex], [tex]K_{B}[/tex] - Initial translational kinetic energies of each particle, measured in joules.
[tex]K[/tex] - Final translational kinetic energy of the collided particles, measured in joules.
By applying the definition of translational kinetic energy, we expand and simplify the equation above:
[tex]\Delta U = \frac{1}{2}\cdot m_{A}\cdot v_{A,o}^{2}+\frac{1}{2}\cdot m_{B}\cdot v_{B,o}^{2} -\frac{1}{2}\cdot (m_{A}+m_{B})\cdot v^{2}[/tex] (3)
If we get that [tex]m_{A} = 4.8\times 10^{-3}\,kg[/tex], [tex]m_{B} = 7.4\times 10^{-3}\,kg[/tex], [tex]v_{A,o} = 3\,\frac{m}{s}[/tex], [tex]v_{B,o} = 0\,\frac{m}{s}[/tex] and [tex]v = 1.180\,\frac{m}{s}[/tex], the internal energy associated with the system is:
[tex]\Delta U = \frac{1}{2}\cdot (4.8\times 10^{-3}\,kg)\cdot \left(3\,\frac{m}{s} \right)^{2}+ \frac{1}{2}\cdot (7.4\times 10^{-3}\,kg)\cdot \left(0\,\frac{m}{s} \right)^{2}-\frac{1}{2}\cdot (4.8\times 10^{-3}\,kg+7.4\times 10^{-3}\,kg)\cdot \left(1.180\,\frac{m}{s} \right)^{2}[/tex]
[tex]\Delta U = 0.013\,J[/tex]
And the initial energy of both particles is:
[tex]E_{o} = \frac{1}{2}\cdot (4.8\times 10^{-3}\,kg)\cdot \left(3\,\frac{m}{s}\right)^{2}+\frac{1}{2}\cdot (7.4\times 10^{-3}\,kg)\cdot \left(0\,\frac{m}{s} \right)^{2}[/tex]
[tex]E_{o} = 0.0216\,J[/tex]
Lastly, the percentage of the original kinetic energy that is convertible to internal energy is: ([tex]\Delta U = 0.013\,J[/tex], [tex]E_{o} = 0.0216\,J[/tex])
[tex]\%e = \frac{\Delta U}{E_{o}}\times 100\,\%[/tex] (4)
[tex]\%e = \frac{0.013\,J}{0.0216\,J}\times 100\,\%[/tex]
[tex]\%e = 60.185\,\%[/tex]
60.185 percent of the original kinetic energy is convertible to internal energy.
A rock dropped from a 5 m height accelerates at 10 m/s and strikes the ground 1 s later. If the rock is dropped
from a height of 2,5 m, its acceleration of fall is
Answer:
10 m/s²
Explanation:
The above question simply indicates motion under gravity.
The acceleration due to gravity (i.e acceleration of free fall) has a constant value of 10 m/s².
Whether the rock is dropped from a height of 5 m or 2.5 m, it will accelerate at 10 m/s² before striking the ground. The only thing that will be different is the time taken for the rock to strike the ground when released from both 5 m and 2.5 m.
Thus, the rock will have a constant acceleration of 10 m/s² irrespective of the height to which it was released.
Since acceleration due to gravity is a constant, the acceleration of the rock dropped from the 5 m height is the same as that dropped from the 2.5 m height and is equal to 10 m/s²
What is the acceleration due to gravity?Acceleration due to gravity is the acceleration a body falling freely from a height above the earth surface which a body experiences due to the gravitational force of attraction of the earth on the body.
Acceleration due to gravity has a constant value which is equal to 10 m/s².
Therefore, the acceleration of the rock dropped from the 5 m height is the same as that dropped from the 2.5 m height and is equal to 10 m/s².
Learn more about acceleration due to gravity at: https://brainly.com/question/11873969
Jared walks 120 m east, 150 m south, and then 40 m west. Find the total
distance traveled by Jared
Answer:
310 m
Explanation:
120+150+40=310
HELP THIS IS DUE IN 5 MINUTES!!!!!!!!!!!! WILL GIVE BRAINLIEST
what is the definition of total velocity?
Answer:
Image result for total velocity definition
The average speed of an object is defined as the distance traveled divided by the time elapsed.
Explanation:
A baseball is thrown across the field. The ____________is measured from where the ball is thrown to where landed was 75 feet.
motion
direction
distance
reference point
Answer:
distance i think
Explanation:
A cable that weighs 4 lb/ft is used to lift 1000 lb of coal up a mine shaft 700 ft deep. Find the work done.
Answer:
980000ft-lbsExplanation:
Step one:
given data
mass of cable= 4lb/ft
mass of coal= 1000lb
dept of mine= 700ft
Step two:
Required
the work-done to lift the coal and the rope combined
Work-done to lift coal
Wc=1000*700= 700,000 lb-ft
Work-done to lift rope
[tex]Wr=\int\limits^{700} _0 {4(700-y)} \, dx \\\\Wr=4(700y-\frac{1}{2}y^2 )\limits^{700}_0[/tex]
substitute y=700 we have, since y=0 will result to 0
[tex]Wr=4(700*700-\frac{1}{2}*700^2 )\\\\Wr=4(490000-245000)\\\\Wr=4(245000)\\\\Wr=980000ft-lbs[/tex]
A spinning ice skater will slow down if she extends her arms away from her body. Which of the following statements explain this phenomenon
A) circular motion is always uniform
B) A centripetal force always points outward
C) Angular momentum is always conserved
D) Centripetal acceleration cannot change
Marking brainliest
Answer:
B, which is why ice skaters often keep their arms close to their body when doing spins and jumps to minimize resistance.
Which current is produced in homes
Answer:
answer is C on edge 2021
Explanation:
While riding a multispeed bicycle, the rider can select the radius of the rear sprocket that is fixed to the rear axle. The front sprocket of a bicycle has radius 12.0 cm. If the angular speed of the front sprocket is 0.600 rev/s, what is the radius of the rear sprocket for which the tangential speed of a point on the rim of the rear wheel will be 5.00 m/s?
Answer:
2.9 cm
Explanation:
Assuming that the rear wheel has a radius of 0.330 m
Given that
r(a) = 12 cm -> 0.12 m
w(a) = 0.6 rev/s -> 3.77 rad/s
v = 5 m/s
r(w) = 0.330 m
The speed on any point on the rim at the sprocket in the front is
v(a) = w(a).r(a) = 3.77 * 0.12 = 0.4524 m/s
Also,
v(a) = speed at any point on the chain
v(b) = speed at any point on the rim of the rear sprocket
v(a) = v(b)
where v(b) = w(b).r(b)
Recall that the speed at any point on the rear wheel is v, where
v = w(b).r(w)
5 = w(b) * 0.330
w(b) = 5/0.330
w(b) = 15.15 rad/s
On substituting this in the equation, we have
v(b) = w(b).r(b).
Remember also, that v(a) = v(b), so
0.4524 = 15.15 * r(b)
r(b) = 0.4524 / 15.15
r(b) = 0.029 m -> 2.9 cm
Therefore, the radius of the rear sprocket needed is 2.9 cm
A repeated back and forth or up and down motion is called a
Answer:
A vibration is a repeated back-and-forth or up-and-down motion.
Explanation:
Waves carry energy through empty space or through a medium without transporting matter.
what happens to the strength of an electromagnet when the voltage in the coils of the solenoid is decreased
Answer:
Make sure you look at the wording!
Explanation:
if the last word is increased, the answer is increased
if the last word is decreased, the answer is it decreases!
a car traveling in a constant speed of 55km/h on a circular track what is the acceleration explain
Answer:
See the explanation below
Explanation:
We must solve this problem by defining that when we have a constant velocity, the acceleration is equal to zero. That is, when there is no speed change, there is no acceleration. We can understand it very easily by means of the following equation of kinematics.
[tex]v_{f}=v_{o}+a*t[/tex]
where:
Vf = final velocity = 55 [km/h]
Vo = initial velocity = 55 [km/h]
a = acceleration [m/s²]
t = time [s]
As we can see there is no change in speed, and the difference between the two is equal to zero.
[tex]0 = 0 +a*t\\a = (0-0)/t\\a= 0[/tex]