Answer:
A: Soil
Explanation:
Protists need a moist environment to survive, and shallow ponds, oceans, and blood is all moist. So, the answer would be the soil, because that is the least moist environment out of these options.
Net force causes motion
Answer:
yes
Explanation:
A physics professor demonstrates the Doppler effect by tying a 600 Hz sound generator to a 1.0-m-long rope and whirling it around her head in a horizontal circle at 100 rpm. Assume the room temperature is 20 degrees Celsius. What are the highest and lowest frequencies heard by a student in the classroom?
Answer:Highest frequency =618.89Hz
Lowest frequency=582.22Hz
Explanation:
The linear velocity of a sound generator is related to angular velocity and is given as
Vs = rω where
r = the radius of circular path = 1.0 m
ω is the angular velocity of the sound generator. = 100 rpm
1 rev/min = 0.10472 rad/s
100rpm =10.472 rad/ s
Vs = rω
= 1m x 10.472rad/ s= 10.472m/s
A) Highest frequency heard by a student in the classroom = Maximum frequency. Using the Doppler effect formulae,
f max = (v/ v-vs) fs
Where , v is the speed of the sound in air at 20 degrees celcius =
343 metres per second
vs is the linear velocity of the sound generator=10.472m/s
fs is the frequency of the sound generator= 600 Hz
f max = (343/ 343 - 10.472) x 600
=343/332.528) x600
=618.89Hz
B) Lowest frequency heard by a student in the classroom = Minimum frequency
f min = (v/ v+vs) fs
(343/ 343 + 10.472) x 600
=343/353.472) x 600
=582.22hz
If a person Travels 100 metre due east and then returns to the same place his total displacement is 200. (needed ASAP)
A. True
B. False
Distance is the total path covered by the object
Here, 200 m is the distance covered by the person and NOT the displacement
Displacement of an object is nothing more than the shortest path between the initial and the final point
If the person travelled 100m and came back, his initial and final point will remain the same which means that he will have a displacement of 0 m
Show the relation among MA, VR and n.
Answer:
good luck!!! sorry I just needed the points xoxo
Explanation:
umm yeah no sorry I tried
A ball is launched from ground level at 20 m/s at an angle of 40° above the
horizontal. A) How long the ball is in the air? B)What is the maximum
height the ball can reach?
(a) The ball's height y at time t is given by
y = (20 m/s) sin(40º) t - 1/2 g t ²
where g = 9.80 m/s² is the magnitude of the acceleration due to gravity. Solve y = 0 for t :
0 = (20 m/s) sin(40º) t - 1/2 g t ²
0 = t ((20 m/s) sin(40º) - 1/2 g t )
t = 0 or (20 m/s) sin(40º) - 1/2 g t = 0
The first time refers to where the ball is initially launched, so we omit that solution.
(20 m/s) sin(40º) = 1/2 g t
t = (40 m/s) sin(40º) / g
t ≈ 2.6 s
(b) At its maximum height, the ball has zero vertical velocity. In the vertical direction, the ball is in free fall and only subject to the downward acceleration g. So
0² - ((20 m/s) sin(40º))² = 2 (-g) y
where y in this equation refers to the maximum height of the ball. Solve for y :
y = ((20 m/s) sin(40º))² / (2g)
y ≈ 8.4 m
If 500 cal of heat are added to a gas, and the gas expands doing 500 J of work on its surroundings, what is the change in the internal energy of the gas?
Answer:
The change in the internal energy of the gas 1,595 J
Explanation:
The first law of thermodynamics establishes that in an isolated system energy is neither created nor destroyed, but undergoes transformations; If mechanical work is applied to a system, its internal energy varies; If the system is not isolated, part of the energy is transformed into heat that can leave or enter the system; and finally an isolated system is an adiabatic system (heat can neither enter nor exit, so no heat transfer takes place.)
This is summarized in the expression:
ΔU= Q - W
where the heat absorbed and the work done by the system on the environment are considered positive.
Taking these considerations into account, in this case:
Q= 500 cal= 2,092 J (being 1 cal=4.184 J) W=500 JReplacing:
ΔU= 2,092 J - 500 J
ΔU= 1,592 J whose closest answer is 1,595 J
The change in the internal energy of the gas 1,595 J
If a 46 kg person walks up two floors in the Physics building (about 10 meters up), this person's potential energy has increased by _____ J.a. 1400 J b. 10,000 J. c. 1000 J. d. 100 J
Answer:
B. 10000 J
Explanation:
The possible answers are not related to the statement at all. The correct statement is:
If a 100 kg person walks up two floors in the Physics building (about 10 meters up), this person's potential energy has increased by:
From definitions of work and gravitational potential, we get the following formula to calculate the change experimented in the person's potential energy after walking up two floors in the Physics building:
[tex]\Delta U_{g} = m\cdot g \cdot \Delta z[/tex] (1)
Where:
[tex]\Delta U_{g}[/tex] - Change in the gravitational potential energy, measured in joules.
[tex]m[/tex] - Mass of the person, measured in kilograms.
[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.
[tex]\Delta z[/tex] - Change in height, measured in meters.
If we know that [tex]m = 46\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex] and [tex]\Delta z = 10\,m[/tex], then the change in the gravitational potential energy is:
[tex]\Delta U_{g} = (100\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot (10\,m)[/tex]
[tex]\Delta U_{g} = 9807\,J[/tex]
The choice that best approximates this answer is B.
A track star runs a 100m race in 12s what is the velocity of the runner?
Answer:
8.33 m/s
Explanation:
v=d/s, velocity = displacement/ time
A cyclist is riding along at a speed of 20.7 when she decides to apply the brakes which gave a deceleration applied was a rate of -3.4 m/s2 over the span of 7.8 s. What distance does she travel over that period of time.
Answer:
The distance is 58.03 m
Explanation:
Constant Acceleration Motion
It occurs when the velocity of an object changes by an equal amount in every equal period of time.
Being a the constant acceleration, vo the initial speed, vf the final speed, and t the time, the following relation applies:
[tex]v_f=v_o+at[/tex]
The distance traveled by the object is given by:
[tex]\displaystyle x=v_o.t+\frac{a.t^2}{2}[/tex]
The conditions of the problem state the cyclist has an initial speed of v0=20.7 m/s during t=7.8 seconds and acceleration of -3.4 m/s^2.
The final speed is:
[tex]v_f=20.7+(-3.4)\cdot 7.8[/tex]
[tex]v_f=20.7-26.52[/tex]
[tex]v_f=-5.82\ m/s[/tex]
Note the cyclist has stopped and come back because his speed is negative. Now calculate the distance:
[tex]\displaystyle x=20.7\cdot 7.8+\frac{(-3.4)\cdot 7.8^2}{2}[/tex]
[tex]\displaystyle x=161.46-103.43[/tex]
x=58.03 m
When you sweat, what is the external stimuli? I need help asap.
Answer:
An External Stimulus is a stimulus that comes from outside an organism. Examples: You feel cold so you put on a jacket. When you sweat, the external stimulus is either you're anxious or hot.
Explanation:
hope it helps! <3
A vertical spring gun is used to launch balls into the air. If the spring is compressed by 4.9 cm, the ball of mass 5.5 g is launched to a maximum height 50.2 cm. How much should the spring be compressed to send the ball twice as high?
We know, by conservation of energy :
[tex]\dfrac{kx^2}{2}=mgh[/tex]
Therefore,
[tex]\dfrac{x_1^2}{x_2^2}=\dfrac{h_1}{h_2}[/tex]
Putting given values, we get :
[tex]\dfrac{x_1^2}{x_2^2}=\dfrac{h_1}{h_2}\\\\\dfrac{4.9^2}{x_2^2}=\dfrac{50.2}{2\times 50.2}\\\\x_2^2=2\times 4.9^2\\\\x_2 = 4.9\times \sqrt{2}\\\\x_2=6.93\ cm[/tex]
Therefore, the spring be compressed to 6.93 cm to send the ball twice as high.
Hence, this is the required solution.
An artificial satellite in a circular orbit around the Sun has a period of 8 years. Determine the ratio of the satellite's orbital radius to that of the earth's orbital radius. Assume that the earth's orbit around the Sun is circular.
Answer:
The ratio is [tex]R_c:R_e = 4 : 1[/tex]
Explanation:
From the question we are told that
The period of the satellite is [tex]T_c = 8 \ years[/tex]
Generally the period of earth around the sun is [tex]T_e = 1 \ year[/tex]
Generally from Kepler's third law , which is mathematically represented as
[tex]\frac{T_c ^2}{T_e^2} = \frac{R_c^3}{R_e^3}[/tex]
Here [tex]R_c[/tex] is the radius of the orbit which the satellite rotate around the sun
[tex]R_e[/tex] is the radius of the orbit which the earth rotate around the sun
=> [tex]\frac{R_c^3}{R_e^3} = [\frac{8}{1} ]^2[/tex]
=> [tex]\frac{R_c}{R_e} = \sqrt[3]{[\frac{8}{1} ]^2}[/tex]
=> [tex]\frac{R_c}{R_e} = \frac{4}{1 }[/tex]
=> [tex]R_c:R_e = 4 : 1[/tex]
If you are pushing 200 kg of textbooks with acceleration of 2m/s2, how much net force are you exerting on the books? (Fnet=ma)
( There is more than one answer)
200N
100N
400Kg
400N
400 kg.m/s2
Explanation:
m=200kg
a=2m/s2
F=ma
F=200kg×2m/s2
=400kg.m/s2 or 400N
You use an electron microscope in which the matter wave associated with the electron beam has a wavelength of 0.0173 nm. What is the kinetic energy of an electron in the beam, expressed in electron volts?
Answer:
The kinetic energy of an electron in the beam is 5.04 keV.
Explanation:
We need to find the velocity of the electron by using the De Broglie wavelength:
[tex] \lambda = \frac{h}{mv} [/tex]
Where:
λ: is the wavelength = 0.0173 nm
v: is the velocity
m: is the electron's mass = 9.1x10⁻³¹ kg
h: is the Planck constant = 6.62x10⁻³⁴ J.s
[tex] v = \frac{h}{m\lambda} = \frac{6.62 \cdot 10^{-34} J.s}{9.1 \cdot 10^{-31} kg*0.0173 \cdot 10^{-9} m} = 4.21 \cdot 10^{7} m/s [/tex]
Now, we can find the kinetic energy:
[tex] E_{k} = \frac{1}{2}mv^{2} = \frac{1}{2}9.1 \cdot 10^{-31} kg*(4.21 \cdot 10^{7} m/s)^{2} = 8.06 \cdot 10^{-16} J*\frac{1 eV}{1.6 \cdot 10^{-19} J} = 5038 eV = 5.04 keV [/tex]
Therefore, the kinetic energy of an electron in the beam is 5.04 keV.
I hope it helps you!
A cylindrical wire of radius 2 mm carries a current of 3.0 A. The potential difference between points on the wire that are 44 m apart is 3.8 V.
Required:
a. What is the electric field in the wire?
b. What is the resistivity of the material of which the wire is made?
Answer:
a. E = 86.36 x 10⁻³ V/m = 86.36 mV/m
b. ρ = 3.6 x 10⁻⁷ Ωm
Explanation:
a.
The electric field in terms of the voltage is given by the following formula:
E = V/d
where,
E = Electric Field in the Wire = ?
V = Potential Difference = 3.8 V
d = distance between the points = 44 m
Therefore,
E = 3.8 V/44 m
E = 86.36 x 10⁻³ V/m = 86.36 mV/m
b.
Now, from Ohm's Law:
V = IR
R = V/I
where,
R = Resistance of wire = ?
I = Current = 3 A
Therefore,
R = 3.8 V/3 A
R = 1.27 Ω
Now, the resistance of a wire can be given as:
R = ρL/A
where,
ρ = resistivity of material = ?
L = Length = 44 m
A = Cross-sectional area = πr² = π(0.002 m)² = 1.25 x 10⁻⁵ m²
Therefore,
1.27 Ω = ρ*44 m/1.25 x 10⁻⁵ m²
(1.27 Ω)(1.25 x 10⁻⁵ m²)/44 m = ρ
ρ = 3.6 x 10⁻⁷ Ωm
Bani wants to know that when a cold wooden spoon is dipped in a cup of hot milk, it transfers heat to its other end by the process of -
Conduction
Convection
Radiation
None of these
Answer:
Conduction is the movement of heat through a substance by the collision of molecules. ... This process continues until heat energy from the warmer object spreads throughout the cooler object, like the heat from the milk spreading throughout the wooden spoon dipped in it. Hence, Option Conduction is correct.
Find the mass of an object on planet F if its weight is 650 N (g = 13m/s^2)
Answer:
the object's mass is 50 kg
Explanation:
We use Newton's second law to solve for the mass:
F = m * a , then m = F / a
In our case, the acceleration is the gravitational acceleration on the planet, and the force is the weight of the object on the planet. So we get:
m = w / a = 650 N / 13 m/s^2 = 50 kg
Then, the object's mass is 50 kg.
explain the relationship among visible light, the electromagnetic spectrum, and sight.
Explanation:
The electromagnetic spectrum is the name given to the full range of frequencies and/or wavelengths that electromagnetic phenomena may have.
Human eyes respond to a small range of wavelengths in that spectrum. That response is called sight. Because humans can see that electromagnetic energy, it is called visible light.
Protists are unique organisms that are so different from each other that they are sometimes called the 'junk drawer' kingdom.
True or False
Answer:
true
Explanation:
Im in k12 and I got an 100%
A 0.20-kg object is attached to the end of an ideal horizontal spring that has a spring constant of 120 N/m. The simple harmonic motion that occurs has a maximum speed of 0.70 m/s. Determine the amplitude A of the motion.
Answer:
The amplitude of the motion is 0.0286 m.
Explanation:
Given;
mass of the object, m = 0.2 kg
spring constant, k = 120 N/m
maximum speed of the simple harmonic motion, [tex]V_m[/tex] = 0.70 m/s
The amplitude A of the motion is given by;
[tex]V_m = \omega A\\\\[/tex]
where;
ω is the angular velocity given as;
[tex]\omega = \sqrt{\frac{k}{m} }\\\\\omega = \sqrt{\frac{120}{0.2} }\\\\\omega =24.5 \ rad/s[/tex]
Now, substitute the value of angular velocity and solve the amplitude;
[tex]V_m = \omega A\\\\A = \frac{V_m}{\omega}\\\\A = \frac{0.7}{24.5}\\\\A = 0.0286 \ m[/tex]
Therefore, the amplitude of the motion is 0.0286 m.
Determine the force of gravitational attraction between a 92 kg student and a 550 g slice of pizza that are 25 cm apart
Answer:
F = 5.4 x 10⁻⁸ N
Explanation:
The gravitational force of attraction between two objects is given by Newton's Gravitational Law as follows:
F = Gm₁m₂/r²
where,
F = Gravitational Force = ?
G = Universal Gravitational Constant = 6.67 x 10⁻¹¹ N.m²/kg²
m₁ = mass of student = 92 kg
m₂ = mass of pizza slice = 550 g = 0.55 kg
r = distance between student and pizza slice = 25 cm = 0.25 m
Therefore,
F = (6.67 x 10⁻¹¹ N.m²/kg²)(92 kg)(0.55 kg)/(0.25 m)²
F = 5.4 x 10⁻⁸ N
Answered: A 4 kg mass is attached to a horizontal spring with the spring constant of 600 N/m and rests on a frictionless surface on the ground. The spring is compressed 0.5 m past its equilibrium. What is the initial energy of the system.
Answer: 75 joules
A block with a mass M = 4.85 kg is resting on a slide that has a curved surface. There is no friction. The speed of the block after it has slid along the slide sufficiently far for its vertical drop to be 19.6 m is:__________a. 19.6 m/s b. 384 m/s c. 93 m/s d. 43.2 m/s e. The problem cannot be solved because the shape of the curved slide is not given.
Answer:
The correct option is a
Explanation:
From the question we are told that
The mass of the block is [tex]m = 4.84 \ kg[/tex]
The height of the vertical drop is [tex]h = 19.6 \ m[/tex]
Generally from the law of energy conservation , the potential energy at the top of the slide is equal to the kinetic energy at the point after sliding this can be mathematically represented as
[tex]PE = KE[/tex]
i.e [tex]m * g * h = \frac{1}{2} * m * v^2[/tex]
=> [tex]gh = 0.5 v^2[/tex]
=> [tex]v = \sqrt{\frac{9.8 * 19.6}{0.5 } }[/tex]
=> [tex]v = 19.6 \ m/s[/tex]
You wish to design a pendulum which moves a mass along an arc of length 40 cm when the angle with the vertical changes by 20 degrees. What should be the length L in meters of the pendulum? Enter the numerical answer without units. Your answer must be within 5% of the exact answer to receive credit.
Answer:
The length of the pendulum cord is approximately 114.592 centimeters.
Explanation:
We include a representation of the motion of the pendulum in the image attached below. The trajectory described by the pendulum is represented by the following geometrical expression:
[tex]s = \theta \cdot r[/tex] (1)
Where:
[tex]\theta[/tex] - Angular change with the vertical, measured in radians.
[tex]r[/tex] - Length of the pendulum cord, measured in centimeters.
[tex]s[/tex] - Arc, measured in centimeters.
If we know that [tex]\theta = \frac{\pi}{9}[/tex] and [tex]s = 40\,cm[/tex], then the length of the pendulum cord is.
[tex]r = \frac{s}{\theta}[/tex]
[tex]r = \frac{40\,cm}{\frac{\pi}{9} }[/tex]
[tex]r \approx 114.592\,cm[/tex]
The length of the pendulum cord is approximately 114.592 centimeters.
Just some Naruto couples having a Boxing Match.
Who do you think will win?! Naruto and Hinata or Pain and Konan?!
Answer:
naruto and hinata
Explanation:
You have a source of energy containing 21 gj of energy at 600k how much this energy can be converted to work when rejecting heat to the atmosphere at 27°C?
Answer:
Available energy = 35 x 10⁶ J
Explanation:
Given:
Amount of energy (Q) = 21 gj = 21 x 10⁹ J
Temperature T1 = 600 k
Temperature T0 = 27 + 273 = 300k
Find:
Available energy
Computation:
Available energy = Q[1/T0 - 1/T1]
Available energy = 21 x 10⁹ J[1/300 - 1/600]
Available energy = 35 x 10⁶ J
10points asap
A force of 30 N acts upon a 7 kg block. Calculate its acceleration.
The batter swings his bat 1.8 meters in 0.1 seconds. How fast is his bat speed in meters per second?
Answer:
18 m/s
Explanation:
1.8 meters / 0.1 seconds = 18 m/s
Which possible component of initial energy is caused by molecular motion within a material?
Answer: thermal energy
Answer:
Thermal energy
Explanation:
The internal energy of a system is widely known as thermal energy. Now, thermal energy is also called heat energy and it is an internal energy of a component which is produced when an increase in temperature causes atoms and molecules within the component to move faster and start colliding with one other.
Therefore, the more heat the is applied to the component, the hotter the substance and the more its particles move which in turn leads to a higher thermal energy.
Are the refractive index and the speed of light in a vacuum direct propotional or inversley
The refractive index of the medium is inversely proportional to the velocity of light in it. As the refractive index of a medium increases, the speed of light going through that medium decreases.