Future space stations could create an artificial gravity by rotating. Consider a cylindrical space station that rotates with a period of 28 seconds about its axis. Astronauts walk on the inside surface of the space station, and they experience an Earth-like gravitational acceleration of 9.8 m/s2. What is the diameter of the space station?
510m
145m
660m
390m
Answer:
P = 2 pi R / v period of space station
F / m = v^2 / R centripetal force per unit of mass
So F / m = 4 pi^2 R^2 / (P^2 * R) = 4 pi^2 R / P^2
Also, F / m = 9.8 m/s^2 earth's gravitational attraction
So 9.8 = 4 pi^2 R / P^2 or R = 9.8 P^2 / 4 * pi^2) = 195 m
Or D = 2 R = 390 m the diameter required
What is the frequency of microwaves of wavelength 3 cm?
Give your answer to the
nearest GHz and without units.
Answer:
10 GHz
Explanation:
Applying,
v = λf.................... Equation 1
Where v = speed of microwave, λ = wavelength, f = frequency.
make f the subject of the equation
f = v/λ................ Equation 2
Note: Microwave is an electromagnetic wave, and all electromagnetic wave have the same speed, which is 3×10⁸ m/s
From the question,
Given: λ = 3 cm = 0.03 m
Constant; v = 3×10⁸ m/s
Substitute these values into equation 2
f = 3×10⁸/(0.03)
f = 10¹⁰ Hz
f = (10¹⁰/10⁹) GHz
f = 10 GHz
A solid, uniform sphere of mass 2.0 kg and radius 1.8 m rolls from rest without slipping down an inclined plane of height 7.5 m. What is the angular velocity of the sphere at the bottom of the inclined plane
Answer:
[tex]w^2=5.5rads/s[/tex]
Explanation:
From the question we are told that:
Mass [tex]m=2.0kg[/tex]
Radius [tex]r=1.8m[/tex]
Height [tex]h=7.5m[/tex]
Generally the equation for Potential energy is mathematically given by
Potential energy=Kinetic energy+Rotational energy
[tex]mgh=\frac{1}{2}mv^2+\frac{1}{2}Iw^2[/tex]
Since there is no slipping
[tex]v=rw[/tex]
Therefore
[tex]mgh=\frac{1}{2}mr^2w^2+\frac{1}{2}Iw^2[/tex]
Where
[tex]I=\frac{1}{2}mr^2[/tex]
[tex]l=3.24m[/tex]
[tex]2*9.81*7.5=\frac{1}{2}(2)(1.8)^2w^2+\frac{1}{2}(3.24)w^2\\\\[/tex]
[tex]147.15=3.24w^2+1.62w^2[/tex]
[tex]w^2=\frac{147.15}{4.86}[/tex]
[tex]w^2=\sqrt{\frac{147.15}{4.86}}[/tex]
[tex]w^2=5.5rads/s[/tex]
If you cut a permanent magnet into four pieces,
you will have what?
A) four temporary magnets
B) four smaller permanent magnets
C) two north poles and two south poles
D)four objects that are no longer magnets
you would have C) two north poles and two south poles
A gondola can carry 20 skiers, with a total mass of up to 2250 kg. The gondola ascends at a constant speed from the base of a mountain, at 2150 m, to the summit at 3345 m. (a) How much work does the motor do in moving a full gondola up the mountain
Answer:
[tex]$2.63\times 10^{7} \ J$[/tex]
Explanation:
Given :
Total mass that a gondola can carry, m = 2250 kg
Displacement, s = 3345 - 2150
= 1195 m
Gravitational force, F = mg
= 2250 x 9.8
= 22050 N
Therefore the work done by the motor in moving the full gondola up the mountain,
W = F x s
= 22050 x 1195
= [tex]$2.63\times 10^{7}$[/tex] J
The instrument measuring the temperature change between inspired cool air and expired warm air is called?
Answer:
It's called a Spirometer
If the height is 10m, what is the potential energy? Asuming that the mass is 10
[tex]\huge{\textit{\sf{{\color{m}{Answer}}{\color{b}{࿐}}}}}[/tex]
we know,
[tex] \boxed{potential \: energy = mgh}[/tex]
So,
[tex]\longmapsto10 \times 9.8 \times 10[/tex]
[tex]\longmapsto980 \: joules[/tex]
A uniform rod of length 80cm rotated in the xy plane about a frictionless pin passing through one end (as shown in figure). If the angular
velocity of the rod is 4rad/s, find the linear velocity (in m/s) of its mid-point C
Rod
Pin
С
Select one:
O a. 0.5
O b. 1.6
O c. 1.3
O d. 0.8
Answer:
Linear velocity (in m/s) = 1.6 m/s
Explanation:
Given:
Length of rotational plane = 80 cm
Angular velocity of the rod = 4rad/s
Find:
Linear velocity (in m/s)
Computation:
Radius from mid point C = Length of rotational plane / 2
Radius from mid point C = 80 / 2
Radius from mid point C = 40 cm
Radius from mid point C = 0.4 m
Linear velocity (in m/s) = Angular velocity of the rod x Radius from mid point C
Linear velocity (in m/s) = 0.4 x 4
Linear velocity (in m/s) = 1.6 m/s
A sample contains radioactive atoms of two types, A and B. Initially there are five times as many A atoms as there are B atoms. Two hours later, the numbers of the two atoms are equal. The half-life of A is 0.77 hours. What is the half-life of B in hours?
Answer:
Explanation:
Initially no of atoms of A = N₀(A)
Initially no of atoms of B = N₀(B)
5 X N₀(A) = N₀(B)
N = N₀ [tex]e^{-\lambda t}[/tex]
N is no of atoms after time t , λ is decay constant and t is time .
For A
N(A) = N(A)₀ [tex]e^{-\lambda_1 t}[/tex]
For B
N(B) = N(B)₀ [tex]e^{-\lambda_2 t}[/tex]
N(A) = N(B) , for t = 2 h
N(A)₀ [tex]e^{-\lambda_1 t}[/tex] = N(B)₀ [tex]e^{-\lambda_2 t}[/tex]
N(A)₀ [tex]e^{-\lambda_1 t}[/tex] = 5 x N₀(A) [tex]e^{-\lambda_2 t}[/tex]
[tex]e^{-\lambda_1 t}[/tex] = 5 [tex]e^{-\lambda_2 t}[/tex]
[tex]e^{\lambda_2 t}[/tex] = 5 [tex]e^{\lambda_1 t}[/tex]
half life = .693 / λ
For A
.77 = .693 / λ₁
λ₁ = .9 h⁻¹
[tex]e^{\lambda_2 t}[/tex] = 5 [tex]e^{\lambda_1 t}[/tex]
Putting t = 2 h , λ₁ = .9 h⁻¹
[tex]e^{\lambda_2\times 2}[/tex] = 5 [tex]e^{.9\times 2}[/tex]
[tex]e^{\lambda_2\times 2}[/tex] = 30.25
2 x λ₂ = 3.41
λ₂ = 1.7047
Half life of B = .693 / 1.7047
= .4065 hours .
= .41 hours .
a 4 kg block is moving at 12 m/s on a horizontal frictionless surface. a constant force is applied such that the block slows with an acceleration of 3 m/s^2. how much work must this force do to stop the block?
a. -576 J
b. -360 J
c. -288 J
d. 360 J
e. 576 J
walk me through this please. NO LINKS.
Answer:
Is there a picture?
Explanation:
Explain the mode of operation of x-ray
Answer:
If x-rays get in touch with our body tissues, they create a picture of a metal film. The high energizing rays are unable to penetrate soft tissue, such as skin and organs and travel through the laser. The places where the x-rays pass soft tissues are Black areas of an X-ray.
Answer:
Explanation:
Mode of Operation: In the X-ray tube a Low voltage high p.d is applied between the hot cathode and the anode. Electrons are emitted from the cathode and are accelerated to an extremely high speed. ... They are produced by increasing the p.d. between the cathode and anode.
The planets and the asteroid belt orbit the Sun in __________. Multiple Choice a spherical distribution, whereas the Oort cloud of comets orbits in a plane planes, whereas the Oort cloud of comets has a spherical distribution orbits nearly identical to the Oort cloud of comets planes tilted at an angle to the plane of the Oort cloud of comets a spherical distribution similar to that of the Oort cloud of comets
Answer:
planes, whereas the Oort cloud of comets has a spherical distribution.
Explanation:
A planet can be defined as a large celestial body having sufficient mass to allow for self-gravity and make it assume a nearly circular shape (hydrostatic equilibrium), revolves in an orbit around the Sun in the solar system and has a cleared neighborhood.
Basically, the planets are divided into two (2) main categories and these includes;
I. Outer planets: these planets are beyond the asteroid belt and comprises of jupiter, saturn, uranus and neptune, from left to right of the solar system.
II. Inner planets: these planets are the closest to the sun and comprises of mercury, venus, earth and mars.
These outer planets are made mostly of gases (hydrogen and helium) causing them to be less dense than the solid inner planets. These gases are generally known to be less dense in terms of physical properties.
Oort cloud is also referred to as Opik and it typically comprises of icy pieces of planetesimals (space debris) that spherically surrounds the sun at distances ranging from about 3000 to 100,000 AU.
Hence, the planets and the asteroid belt orbit the Sun in planes, whereas the Oort cloud of comets has a spherical distribution.
An ant is crawling along a straight wire, which we shall call the x axis, from A to B to C to D (which overlaps A), as shown in the figure below. O is the origin. Suppose you take measurements and find that AB is 31 cm , BC is 12 cm , and AO is 7 cm .(Figure 1)
A. What is the ant’s position at point A?
B. What is the ant’s position at point B?
C. What is the ant’s position at point C?
D. What is the ant’s position at point D?
Answer:
Ants position at point A = -7 cm
Ants position at point B = 38 cm
Ants position at point C = 26 cm
Ants position at point D = -7 cm
Explanation:
In this question, we are dealing with displacement which is the change in position of an object.
Now, we are told the journey began from A to B and then from C to D.
Now, AB = 31 cm and AO = 7cm
But along AB, we have the origin O.
Since A is on the left hand side of the origin, it means it is negative. Thus, position A = -7cm
Then position B = 31 - (-7) = 31 + 7 = 38 cm
Since BC = 12cm, then position C = 38 - 12 = 26 cm
Position D is same as position A = -7cm
A system is in liquid-vapor mixture of 0.5 kg of saturated water vapor and 0.5 kg
of saturated liquid. Calculate the quality.
Answer:
x = 0.5 = 50%
Explanation:
The quality of a water liquid-vapor mixture can be defined as the fraction of water vapor present in the water liquid-vapor mixture. Therefore, it can be calculated by the use of the following formula:
[tex]x = \frac{m_{vap}}{m}[/tex]
where,
x = quality = ?
m_vap = mass of saturated water vapor = 0.5 kg
m = total mass = mass of saturated vapor + mass of saturated liquid
m = 0.5 kg + 0.5 kg = 1 kg
Therefore,
[tex]x = \frac{0.5\ kg}{1\ kg}[/tex]
x = 0.5 = 50%
what determines the strength of a base?
The higher the dissociation constant the stronger the acid or base. Since electrolytes are created as ions are freed into solution there is a relationship between the strength of an acid, a base, and the electrolyte it produces. Acids and bases are measured using the pH scale.
If a body of mass 2 kg is moving with a velocity of 30 m/s, then on doubling its velocity the momentum becomes______.
a-60kgm/s
b-120kgm/s
c-90kgm/s
D-30kgm/s
A horizontal wire supports it weight in a 0.001T magnetic field, oriented orthogonally to the wire. This is due to current running from left to right in the wire. Calculate the current through this wire that will just support the weight of the wire (over the length of the wire). The length of the wire is 0.5 m, and the mass of the 0.5 m section is 50 g. [give your answer in units of Amps]
Answer:
Explanation:
Force on a current carrying wire in a magnetic field
= B i L where B is magnetic field , i is current and L is length of the wire .
Putting in the given values in the question
force on a current carrying wire in a magnetic field = .001 T x i x .5 m
5 x 10⁻⁴ i N .
weight of the wire = .050 kg x 9.8 m/s²
= .49 N .
For equilibrium
5 x 10⁻⁴ i = .49
i = 980 A .
Descriptions of the sky at various locations on Earth
In the diagram shown below, the distance from the dotted line to Point A, or the distance from the dotted line to Point D is known as the
Answer:
The dotted line connecting two points is known as the distance traveled.
Explanation:
The distance traveled is a physical quantity that refers to the total displacement of a body. This distance is usually shown as a dotted line that connects two points in an image. In general, we can say that the distance traveled is calculated by adding all the distances that an element makes when leaving one point and reaching another point, which is its final position.
An example of this can be seen in the image shown below, where the red line represents the displacement of a body that left point A and arrived at point B. The blue dotted line represents the distance traveled and refers to the total displacement of that body, showing all the distances it covered while walking from point A to point B.
a particle covers 10m distance in 2sec. if final velocity is 8m/s, find initial velocity
Answer:
vi =2
Explanation:
Δx = 1/2 (vi + vf) t
10 = 1/2 ( vi + 8 ) 2
10 = vi + 8
10-8 = vi
vi = 2 m/s
vi= initial velocity
vf= final velocity
Δx= distance
t= time
What does the potential energy diagram of a chemical reaction tell you?
O A. Whether atoms are being created or destroyed
O B. Whether the reaction is endothermic or exothermic
C. Whether there are more reactants or products
D. Whether the law of conservation of matter is being obeyed
Answer:
B
Explanation:
I'm learning about this now actually and it can be a little confusing but it would be endothermic or exothermic. if endothermic the products have less energy than the reactants and if exothermic products have more energy than reactants
A piece of stone of mass 80 g is
dropped into a measuring cylinder
containing water. The water level
increases from 12 cm² to 37 cm
Calculate the density of the stone.
A. 32 g/cm
B. 3.2 g/cm
C. 320 g/cm
D. 3.20 g/cm
8
37+12
Answer:
this is how I know it though my answer is not in the choices
Explanation:
M=80g
V=37cm-12 cm
15cm
Density=mass/volume
80g/15cm3
5.33g/cm3
DESCRIBE THE REQUIREMENTS OF AN INTERNET CONNECTION?
please tell me the answer
Answer: The basic requirements for connecting to the Internet are a computer device, a working Internet line, and the right modem for that Internet line. In addition, software programs such as Internet browsers, email clients, Usenet clients, and other special applications are needed in order to access the Internet.
Explanation: brainleist pls :)
You throw a ball straight up. Compare the sign of the work done by gravity while the ball goes up with the sign of the work done by gravity while it goes down.
a. Work is + on the way up and + on the way down
b. Work is + on the way up and - on the way down
c. Work is - on the way up and + on the way down
d. Work is - on the way up and - on the way down
Answer:
c. Work is - on the way up and + on the way down
Explanation:
Work done is given as the product of the applied force and the displacement of the object.
Work done = F x d
Work done = mg x d
where;
g is acceleration due to gravity = 9.8 m/s²
When the ball goes up, it moves against the force of gravity which tends to pull every object downwards. Since the ball moves against gravity, the work done is negative.
Also, when the ball goes down, it moves in the direction of gravity which acts downwards. Since the ball moves in the same direction as gravity, the work done is positive.
The correct option is "C. Work is negative (-) on the way up and positive (+) on the way down"
What are 3 facts you learned about the periodic table:
Answer: the rarest element is Francium. J is not on the periodic table. also Dmitri Mendeleev proposed the periodic table.
Explanation: Kinda looked the last one up.
In an electric resistance of 20 ohms, if the current intensity passing through it
is doubled, its value becomes ........ ohms.
b. 20
d. 40
a. 10
c. 30
Answer:
a. 10 ohms.
Explanation:
Given;
first electrical resistance, r₁ = 20 ohms
let the first current through the circuit = I₁
let the second current through the circuit, I₂ = 2I₁ (since it is doubled)
then, the new value of the resistance after doubling the current = r₂
the current intensity is given as;
[tex]\frac{dI}{dt} = I = \frac{v}{r} \\\\I_1r_1 = I_2r_2\\\\r_2 = \frac{I_1r_1}{I_2} \\\\r_2 = \frac{I_1 \times 20}{2I_1 } \\\\r_2 = 10 \ ohms[/tex]
Therefore, the new value of the resistance is 10 ohms.
Un corredor hace los 400 metros lisos en 50 seg. Calcula la velocidad en la carrera.
Answer:
8 meters/second
Explanation:
Rate x Time = Distance
R x T = D
R x 50sec = 400meters
R x 50sec/50sec = 400meters/50sec
R = 8meters/sec
which of the following changes will increase the frequency of an oscillating pendulum?
a. an increase in the mass of the pendulum.
b. an increase in the initial height of release.
c. an increase in the length of the rope.
d. more than one of the above
e. none of the above
explain your answer in your own words.
NO LINKS.
Answer:
b (i think)
Explanation:
Which quantity does not change when there is an increase in temperature?
Answer:
But Mass of solids does not depend upon the temperature because it is matter contained in the solids.
Explanation:
The mass is the quantity which does not change when there is an increase in temperature.
What is mass?A tangible body's mass is the amount of matter it possesses. It's also a metric of inertial, or the resistance to velocity when a net force is exerted.
The quantity does not change when there is an increase in temperature is mass because it is matter that makes up solids, their mass is unaffected by temperature.
Thus, the mass is the quantity which does not change when there is an increase in temperature.
Learn more about the mass here:
https://brainly.com/question/15959704
#SPJ2
Does the law of attraction actually have a basis in physics?
Answer:
Scientific theories are cited by proponents of the Law of Attraction as evidence in its favor. It, on the other hand, has no theoretical basis. A variety of scientists have questioned the promoters' abuse of scientific principles.