Answer:
swimming, cycling, jump rope, brisk walking, gardening, jogging
Which of the following statements is true?
A. Friction primarily affects objects that contain iron.
B. Friction pulls objects toward the center of the Earth
C.
Friction does not affect objects in motion.
D.
Friction slows down or stops objects in motion.
Answer:
D. Friction slow down or stop objects in motion.
The speed of propagation of the action potential (an electrical signal) in a nerve cell depends (inversely) on the diameter of the axon (nerve fiber). If the nerve cell connecting the spinal cord to your feet is 1.3 m long, and the nerve impulse speed is 33 m/s, how long (in s) does it take for the nerve signal to travel this distance?
Answer:
Explanation:
Speed of electrical nerve signal = 33 m /s
Distance travelled = 1.3 m
time taken = distance / speed
= 1.3 / 33
= .039 s
= 39 ms ( millisecond ) .
Which one of Newton’s Laws best explains a bottle flip?
Answer:
the 2nd law-
Hope this helps <3
Explanation:
attraction is seen between the poles of two bar magnet in the case of
Answer:
he magnetic field of a bar magnet is strongest at either pole of the magnet. It is equally strong at the north pole when compared with the south pole. The force is weaker in the middle of the magnet and halfway between the pole and the centerExplanation:
Concept Simulation 4.1 reviews the central idea in this problem. A boat has a mass of 4490 kg. Its engines generate a drive force of 4520 N due west, while the wind exerts a force of 890 N due east and the water exerts a resistive force of 1210 N due east. Take west to be the positive direction. What is the boat's acceleration, with correct sign
Answer:
-0.54m/s²
Explanation:
According to Newton's second law of motion
F = ma
Force = mass * acceleration
Given
Mass m = 4490kg
Take the sum of forces
Sum of force along the east = 890+1210 = 2100N
Sum of forces along the west = -4520N
Net force = -4520+2100
Net force = -2420N
Acceleration = Net force/Mass
Acceleration = -2420/4490
Acceleration = -0.54m/s²
Hence the boat acceleration is -0.54m/s²
If a wave has a speed of 1000 m/s and frequency of 500 Hz, what is the wavelength?
• 1500 Hz
• 2 m
• 0.05 m
Answer:
2 m
Explanation:
speed=frequency×wavelength
wavelength=speed/frequency
wavelength=1000/500
=2 m
who has brown hair and brown eyes but is a boy
Answer:
I have strawberry blonde/brown hair blue eyes and a girl lol
Explanation:
How long will it take an object traveling at 90 kilometers per hour to travel 910 kilometers?
Explanation:
time = distance / velocity
We know that distance = 910 km and velocity = 90 km/h.
t = d / v
t = 910 km / 90 km/h
t = 10.11 hrs
The object traveled for 10.11 hours long. Hope this helps, thank you !!
How can you drop two eggs the fewest amount of times, without them breaking?
Answer:
get 2 jugs of water put an egg in each one drop the jugs with parachutes on them in long grass on a sunny non windy day
Explanation:
egg+ground=broken
egg-ground= egg+air
egg+air=unbroken
egg+water= egg+wet
egg+water= unbroken
egg+egg= 2 egg
egg+egg+air= egg+egg+unbroken+unbroken
egg+egg+unbroken+unbroken=(egg+unbroken)2
longgrass+egg= 40%unbroken+60broken+egg
longgrass+egg+egg=20%unbroken+80%broken+2egg
ground+water=mud
mud+egg=unbroken+egg+muddy
air+water=raining
egg+raining+air=wet+egg+slip+50%broken+50%unbroken
ask if need more proof
The physics of wind instruments is based on the concept of standing waves. When the player blows into the mouthpiece, the column of air inside the instrument vibrates, and standing waves are produced. Although the acoustics of wind instruments is complicated, a simple description in terms of open and closed tubes can help in understanding the physical phenomena related to these instruments. For example, a flute can be described as an open-open pipe because a flutist covers the mouthpiece of the flute only partially. Meanwhile, a clarinet can be described as an open-closed pipe because the mouthpiece of the clarinet is almost completely closed by the reed.
Consider a pipe of length 80.0 cm open at both ends. What is the lowest frequency f of the sound wave produced when you blow into the pipe?
Answer:
Explanation:
Lowest frequency will be the fundamental frequency . For fundamental note
λ /2 = L where λ is wavelength of sound produced and L is length of open end pipe .
Given L = 80 cm
λ /2 = 80
λ = 160 cm .
= 1.6 m
frequency of note = velocity of sound / wavelength
= 330 / 1.6
= 206.25 Hz .
206 Hz approx.
pls help me this is a major SOS pls help pls btw this is IXL
Explanation:
the object with the higher temperature has greater thermal energy
So the answer is
the stick of butter with less thermal energy.
Hope it will help :)
Answer:
The stick of butter with less thermal energy
Explanation:
I am pretty sure
Calculate the ratio of the drag force on a passenger jet flying with a speed of 1200 km/h at an altitude of 10 km to the drag force on a prop-driven transport flying at one-fourth the speed and half the altitude of the jet. At 10 km the density of air is 0.38 kg/m3 and at 5.0 km it is 0.67 kg/m3. Assume that the airplanes have the same effective cross-sectional area and the same drag coefficient C. (drag on jet / drag on transport)
Answer:
[tex]2.267[/tex]
Explanation:
Drag force is given by
[tex]F=\dfrac{1}{2}\rho Av^2C[/tex]
C = Drag coefficient is constant
A = Area is constant
[tex]v_1[/tex] = Velocity of the passenger jet = 1200 km/h = [tex]\dfrac{1200}{3.6}\ \text{m/s}[/tex]
[tex]v_2[/tex] = Velocity of the prop plane = [tex]\dfrac{1}{4}v_1[/tex]
[tex]\rho_1[/tex] = Density of the air where the jet was flying = [tex]0.38\ \text{kg/m}^3[/tex]
[tex]\rho_2[/tex] = Density of the air where the prop plane was flying = [tex]0.67\ \text{kg/m}^3[/tex]
[tex]F\propto \rho v^2[/tex]
[tex]\dfrac{F_1}{F_2}=\dfrac{\rho_1 v_1^2}{\rho_2 v_2^2}\\\Rightarrow \dfrac{F_1}{F_2}=\dfrac{0.38 v_1^2}{0.67 (\dfrac{1}{4}v_1^2)}\\\Rightarrow \dfrac{F_1}{F_2}=2.267[/tex]
The ratio of the drag forces is [tex]2.267[/tex].
Two students are on a balcony a distance h above the street. One student throws a ball vertically downward at a speed vi; at the same time, the other student throws a ball vertically upward at the same speed. Answer the following symbolically in terms of vi, g, h, and t. (Take upward to be the positive direction.)
(a) What is the time interval between when the first ball strikes the ground and the second ball strikes the ground?
?t = ______
(b) Find the velocity of each ball as it strikes the ground.
For the ball thrown upward vf = ______
For the ball thrown downward vf = ______
(c) How far apart are the balls at a time t after they are thrown and before they strike the ground?
d = _______
Answer:
Explanation:
a )
Time for first ball to reach top position
v = u - gt
0 = vi - gt
t = vi / g
Time to reach balcony while going downwards
= vi /g
Total time = 2 vi / g
Time to go down further to the ground = t₁
Total time = 2 vi / g + t₁
Time for the other ball to go to the ground = t₁
Time difference = ( 2 vi / g + t₁ ) - t₁
= 2vi / g .
( b )
v² = u² + 2gh
For both the throw ,
final displacement = h , initial velocity downwards = vi
( For the first ball also , when it go down while passing the balcony , it acquires the same velocity vi but its direction is downwards.)
vf² = vi² + 2gh
vf = √ ( vi² + 2gh )
(c )
displacement of first ball after time t
s₁ = - vi t + 1/2 g t² [ As initial velocity is upwards , vi is negative ]
displacement of second ball after time t
s₂ = vi t + 1/2 g t²
Difference = d = s₂ - s₁
= vi t + 1/2 g t² - ( - vi t + 1/2 g t² )
d = 2 vi t .
Problem 4.13: Sound waves travel through air at a speed of 330 m/s. A whistle blast at a frequency of about 1.0 kHz lasts for 2.0 s. (a) Over what distance in space does the "wave train" representing the sound extend? (b) What is the wavelength of the sound? (c) Estimate the precision with which an observer could measure the wavelength. (d) Estimate the precision with which an observer could measure the frequency.
Answer:
a) x = 660 m, b) λ = 0.330 m, c) Δλ = 0.1 cm, d) Δf = 104
Explanation:
a) the distance in which the train of waves extends can be obtained from the uniform movement
v = x / t
x = v t
x = 330 2
x = 660 m
b) the speed of sound is related to the wavelength and frequency
v = λ f
λ = v / f
λ = 330/1000
λ = 0.330 m
c) The precision in the measurement of the wavelength refers to the error or uncertainty in the measurement, if the measurement is direct with a tape measure the precision is the appreciation of the tape measure, in general it is 0.1 cm
d) the accuracy of the frequency in general the frequency is calculated from the measurements of period T
f = 1 / T
The precision of the period is data by the chronometer used, in general time a press of 0.01s, by the response time of the people
Δf = df / dT ΔT
Δf = 1 / T² ΔT
Δf = 1 / (0.001)² 0.01
Δf = 104
As we can see, a much more precise system is needed to reduce the error
A radio transmitting station operating at a frequency of 125 MHz has two identical antennas that radiate in phase. Antenna B is 9.05 m to the right of antenna A. Consider point P between the antennas and along the line connecting them, a horizontal distance x to the right of antenna A. For what values of x will constructive interference occur at point P?
Answer:
Explanation:
The formula for frequency is:
[tex]f = \dfrac{c}{\lambda}[/tex]
If we make [tex]\lambda[/tex] the subject; we have:
[tex]\lambda = \dfrac{c}{f}[/tex]
[tex]\lambda = \dfrac{3\times 10^6 \ m/s}{125 \ MHz (\dfrac{10^6 \ Hz}{1 \ MHz})}[/tex]
[tex]\lambda = 2.4 \ m[/tex]
Let assume that there is a point P between antenna A to B.
where;
A to B = 9.05
A to P = x and
P to B = 9.05 - x
Then, the condition for the constructive inteference is:
Δx = nλ
x - (9.05 - x) = nλ
2x - 9.05 = n(2.4)
So, we need to start assigning values to n so that the value of x becomes less than or equal to 9.05 m
If n = -1
Then;
2x - 9.05 = (-1)(2.4)
x = 3.325 m
If n = -2
Then;
2x - 9.05 = (-2)(2.4)
x = 2.125 m
If n = -3
Then;
2x - 9.05 = (-3)(2.4)
x = 0.925 m
If n = 0
Then;
2x - 9.05 = (0)(2.4)
x = 4.525 m
If n = 1
2x - 9.05 = (1)(2.4)
x = 5.725 m
If n = 2
Then;
2x - 9.05 = (2)(2.4)
x = 6.925 m
Hence, there exist 7 points in which constructive interference occurs.
Which of the following choices is the best example of potential energy?
Answer:
A basketball sitting still in a players hands
Explanation:
The other 3 answers have the ball in motion (going towards the basket, bouncing, and rolling) so that would be kinetic energy.
When the basketball is sitting in the player's hands, it has the potential to be in motion.
Answer:
it is D not B it D
Explanation:
PLZZZZ HELPPPPPPPPPppppp
A shuttle bus slows down with an average acceleration of -2.4 m/s2. How long does it
take the bus to slow from 9.0 m/s to rest?
Answer:
[tex]\boxed {\boxed {\sf 3.75 \ seconds }}[/tex]
Explanation:
Average acceleration is found by dividing the change in acceleration by the time.
[tex]a=\frac{ v_f-v_i}{t}[/tex]
The shuttle bus has an acceleration of -2.4 meters per square second. It slows from 9.0 meters per second to rest, or 0 meters per second. Therefore:
[tex]a= -2.4 \ m/s^2 \\v_f= 0 \ m/s \\v_i= 9 \ m/s[/tex]
Substitute the values into the formula.
[tex]-2.4 \ m/s^2=\frac{0 \ m/s - 9 \ m/s}{t }[/tex]
Solve the numerator.
[tex]-2.4 \ m/s^2 = \frac{-9 \ m/s}{t}[/tex]
We want to solve for t, the time. We have to isolate the variable. Let's cross multiply.
[tex]\frac{-2.4 \ m/s^2}{1} = \frac{-9 \ m/s}{t}[/tex]
[tex]-9 \ m/s *1= -2.4 \ m/s^2 *t[/tex]
[tex]-9 \ m/s=-2.4 m/s^2*t[/tex]
t is being multiplied by -2.4. The inverse of multiplication is division, so divide both sides by -2.4
[tex]\frac{-9 \ m/s }{-2.4 \ m/s^2} =\frac{ -2.4 \ m/s^2*t}{-2.4 \ m/s^2}[/tex]
[tex]\frac{-9 \ m/s }{-2.4 \ m/s^2} =t[/tex]
[tex]3.75 \ s=t[/tex]
It takes 3.75 seconds.
A long, circular aluminum rod is attached at one end to a heated wall and transfers heat by convection to a cold fluid. If the diameter of the rod is doubled, by how much would the rate of heat removal change
Complete question is;
A long, circular aluminum rod is attached at one end to a heated wall and transfers heat by convection to a cold fluid. If the diameter of the rod is doubled, by how much would the rate of heat removal change?
Answer:
182.84 %
Explanation:
Formula for rate of heat transfer of an infinite log fin is given as;
q_f1 = (π/2) × (hk)^(½)) × D^(3/2)) × (T_b - T_∞)
Where D is diameter.
Now, if the diameter of the rod is doubled, it means Diameter is now 2D.
Thus;
q_f2 = (π/2) × (hk)^(½)) × (2D^(3/2)) × (T_b - T_∞)
To find how much the rate of heat removal will change, we will calculate as follows;
((q_f2/q_f1) - 1) × 100
Plugging in the relevant expressions, we have;
([[(π/2) × (hk)^(½)) × ((2D)^(3/2)) × (T_b - T_∞)]/[(π/2) × (hk)^(½)) × (D^(3/2)) × (T_b - T_∞)]] - 1) × 100
Upon simplifying, we have;
(((2D)^(3/2))/(D^(3/2)) - 1) × 100
((2^(3/2)) - 1) × 100
This gives;
182.84 %
Which two statements help explain why digital storage of data is so reliable?
A. Memory chips are sturdy.
U B. Digital data usually deteriorate over time.
C. It is usually possible to recover data from a memory chip even
when the device containing it is broken.
D. Digital data are easier to copy than analog data are, making them
more accessible to thieves.
Answer:
A. Memory chips are sturdy.
C. It is usually possible to recover data from a memory chip even when the device containing it is broken.
Explanation:
Digital storage of data refers to the process which typically involves saving computer files or documents on magnetic storage devices usually having flash memory. Some examples of digital storage devices are hard drives, memory stick or cards, optical discs, cloud storage, etc.
A reliable storage ensures that computer files or documents are easily accessible and could be retrieved in the event of a loss.
The two statements which help explain why digital storage of data is so reliable are;
A. Memory chips are sturdy: they are designed in such a way that they are compact and firm.
C. It is usually possible to recover data from a memory chip even when the device containing it is broken.
Answer:
A and C
Explanation:
got it right on a p e x
How far can a bus carrying small children, travel at a rate of 60 km per hour travel in 2 1/2 hours?
Explanation:
speed = 60km/hr.time = 2¹/2 hr = 5/2 hrdistance = speed × time = 60 ×5/2 = 150kmMARK ME AS BRAINLIST|:Give one word answer
1. An object that allows whole light to pass through it _______
Answer:
Translucent object
Explanation:
A vertical wire carries a current straight up in a region of the magnetic field directed north. What is the direction of the magnetic force on the current due to the magnetic field
Answer:
The direction of the force on the vertical wire is towards the East or right.
Explanation:
Using Fleming's right hand rule, the current is the middle finger pointing straight up, the magnetic field is the fore-finger pointing Northwards and then the thumb is the direction of the force on the vertical wire.
Following these conventions, the thumb points towards the East. So, the direction of the force on the vertical wire is towards the East or right.
An insulated, vertical piston-cylinder assembly contains 50 L of steam at 105 oC. The outside pressure is 101 kPa. The piston has a diameter of 20 cm and the combined mass of the piston and the load is 75 kg. The electrical heater and the paddle wheel are turned on and the piston rises slowly by 25 cm with a constant pressure. The total internal energy increases by 3.109 kJ.
Determine:
a. The pressure of air inside the cylinder during the process.
b. The boundary work performed by the gas.
c. The combined work transfer by the shaft and electricity.
Answer:
Explanation:
From the given information:
The pressure of the air during the process = [tex]P_{atm} + P_{due \ to \ wt \ of \ piston}[/tex]
[tex]= 101 \ kPa + \dfrac{75 \ kg \times 9.8 \ m/s^2 \times \dfrac{1 \ N }{1 \ kg.m/s^2} }{\dfrac{\pi}{4}(0.2 \ m)^2} ( \dfrac{1 \ N }{m^2} \times \dfrac{1 \ kPa}{1000 \ n/m^2})[/tex]
The pressure of the air during the process = 124.42 kPa
The boundary work = P × ΔW
The boundary work = 124.42 kPa × (π/4) × (0.2 m)² × 0.25 m × (1 kJ/1 kPa.m³)
The boundary work = 0.977 kJ
The combined work transfer = [tex]W_{boundary} + \Delta U[/tex]
The combined work transfer = 0.977 + 3.109 kJ
The combined work transfer = 4.086 kJ
what is the formular for force
Answer:
f=m*a
Explanation:
The formula for force says force is equal to mass (m) multiplied by acceleration (a)
The electric field from two charges in the plane of the paper is represented by the dashed lines and arrows below.
Select a response for each statement below. (Use 'North' towards top of page, and 'East' to the right)
The magnitude of the E-field at Ris .... than at M.
The force on a (+) test charge at P is zero.
The magnitude of the charge on the left is .... that on the right.
The force on a (+) test charge at L is directed ....
The force on a (-) test charge at J is directed
The force on a (-) test charge at N is directed ....
The sign of the charge on the right is negative.
Answer:
a) electric field at point P must be zero
b) harged must be positive
c) force ais in the direction of the electric field
d) force is in the opposite direction to the electric field
e) force is in the opposite direction to the field
Explanation:
After reading your exercise, it is unfortunate that the diagram did not come out, but we are going to answer the questions in general.
a) force on a charge (+) is zero
this implies that the electric field at point P must be zero
F = q E
b) the magnitude of the charge on the left is on the right
this indicates that the charged must be positive since the lines must exit the charge
c) force on load directed towards (direction not indicated)
since the charge is positive the force at point L is in the direction of the electric field at this point
d) force on test load (-) does not indicate direction
The force on a negative charge is in the opposite direction to the electric field at point J
e) Force on a test load (-) at point N
the force is in the opposite direction to the field at point N
Communication satellites are placed in a geosynchronous orbit, i.e., in a circular orbit such that they complete one full revolution about the earth in one sidereal day (23.934 h), and thus appear stationary with respect to the ground. Determine the altitude of these satellites above the surface of the earth in both SI and U.S. customary units.
Answer:
Explanation:
Let the radius of orbit of geostationary satellite be R .
Time period of satellite = 2πR / V₀ where V₀ is orbital velocity
T = 2πR / √gR
T= 2πR / √(GM / R )
T = 2πR¹°⁵ / √GM
R¹°⁵ = T x √GM / 2π
T = 23.934 h = 23.934 x 60 x 60 s = 86126.4 s
R¹°⁵ = 86126.4 x √ ( 6.67 x 10⁻¹¹ x 5.972 x 10²⁴ ) / 2π
= 86126.4 x √ ( 398.33 x 10¹² ) / 2π
= 86126.4 x 19.95 x 10⁶ / 2π
= 273.428 x 10⁹
R = 42.92 x 10⁶ m
= 42920 km
Radius of orbit = 42920 km
radius of earth = 6370 km
Altitude of satellite = 42920 - 6370 = 36550 km .
In US customary unit = 36550 x 10³ /.9144 yards
= 36550 x 10³ /(.9144 x 1760 ) miles
= 22771 miles .
Which statement accurately describes a relationship between parts of the
universe?
O A. There are millions of nebulae in a star.
O B. There are thousands of universes in a galaxy.
C. There are trillions of galaxies in the universe.
O D. There are billions of galaxies in a solar system.
Answer:
C. There are trillions of galaxies in the universe.
Explanation:
A. is wrong as nebulae are found inside galaxies and inside the universe, not inside stars.
B. is wrong because there are trillions of galaxies in the universe, not the latter.
D. The solar system consists of the eight planets, the Sun, comets, meteors, dwarf planets, and is inside the Milky Way galaxy and thus cannot have galaxies inside it.
Please give Brainliest
Answer:
C.
Explanation:
There are trillions of galaxies in the universe.
Explain the difference in the function of plant and animal cell organelles, including cell membrane, cell wall, nucleus, cytoplasm, mitochondria, chloroplast, and vacuole
Answer:
Plant cell Animal cell
2. Have a cell membrane. 2. Have no chloroplasts.
3. Have cytoplasm. 3. Have only small vacuoles.
4. Have a nucleus. 4. Often irregular in shape.
5. Often have chloroplasts
containing chlorophyll. 5. Do not contain plastids.
who is bill cypher and what is his origin?
Answer:
Bill Cipher is the true main antagonist of Gravity Falls. He is a Dream-Demon with mysterious motives and seems to have a vendetta against the Pines family, especially his old rival Stanford Pines
Explanation: