Imagine you leave the dock on a fishing boat that travels east for 30 kilometers when the captain realizes he left the fishing rods on the dock. It takes him 40 minutes to travel out against the current but only 20 minutes to return to the dock.
Answer:
Average speed is 60 km/hr whereas average velocity is 0 km/ hr.
Explanation:
The average speed of the boat is 60 km/ hr while on the other hand, the average velocity of the boat is 0 km/ hr because average speed is the total distance covered by the boat in total time and average velocity is the displacement covered by the boat in total time. The total distance covered by the boat is 60 km and the total time is 60 minutes which is equals to one hour so the answer is 60 km/hr whereas the displacement is the shortest distance between initial and final position which is 0 in this case so 0 divided by 60 minutes or one hour is also 0.
A point source emits sound waves with a power output of 135 watts. What is the sound level (in dB) at a distance of 10 m
Answer:
The sound level of the point source at a distance of 10 meters is approximately 110.294 decibels.
Explanation:
First, we calculate the intensity ([tex]I[/tex]), in watts per square meter, by the Inverse-Square Law:
[tex]I= \frac{\dot W}{4\pi\cdot r^{2}}[/tex] (1)
Where:
[tex]\dot W[/tex] - Power, in watts.
[tex]r[/tex] - Radius, in meters.
And the sound intenity level ([tex]L[/tex]), in decibels, is expressed by:
[tex]L = 10\cdot \log_{10} \frac{I}{I_{o}}[/tex] (2)
Where [tex]I_{o}[/tex] is the reference sound intensity, in watts per square meter.
If we know that [tex]\dot W = 135\,W[/tex], [tex]r = 10\,m[/tex] and [tex]I_{o} = 10^{-12}\,\frac{W}{m^{2}}[/tex], then we find that sound level at a distance of 10 meters is:
[tex]I= \frac{\dot W}{4\pi\cdot r^{2}}[/tex]
[tex]I = 0.107\,\frac{W}{m^{2}}[/tex]
[tex]L = 10\cdot \log_{10} \frac{I}{I_{o}}[/tex]
[tex]L \approx 110.294\,dB[/tex]
The sound level of the point source at a distance of 10 meters is approximately 110.294 decibels.
A 20-gram bullet traveling at 250 m/s strikes a block of wood that weighs 2 kg. With what velocity will the block and bullet move after the collision? [convert g to kg]
Answer:
the velocity of the bullet-wood system after the collision is 2.48 m/s
Explanation:
Given;
mass of the bullet, m₀ = 20 g = 0.02 kg
velocity of the bullet, v₀ = 250 m/s
mass of the wood, m₁ = 2 kg
velocity of the wood, v₁ = 0
Let the velocity of the bullet-wood system after collision = v
Apply the principle of conservation of linear momentum to calculate the final velocity of the system;
Initial momentum = final momentum
m₀v₀ + m₁v₁ = v(m₀ + m₁)
0.02 x 250 + 2 x 0 = v(2 + 0.02)
5 + 0 = v(2.02)
5 = 2.02v
v = 5/2.02
v = 2.48 m/s
Therefore, the velocity of the bullet-wood system after the collision is 2.48 m/s
A young boy swings a yo-yo horizontally above his head so that the yo-yo has a centripetal acceleration of 200 m/s^2. If the yo-up’s string is 0.33 m long, what is the yo-up’s tangential speed?
Answer:
v = 8.12 m/s
Explanation:
The centripetal acceleration of the yo-yo is given by the following formula:
[tex]a_c = \frac{v^2}{r}\\\\v^2 = a_cr\\v = \sqrt{a_cr}[/tex]
where,
v = tangential speed = ?
ac = centripetal acceleration = 200 m/s²
r = radius = length of string = 0.33 m
Therefore, using the given values in the formula, we get:
[tex]v = \sqrt{(200\ m/^2)(0.33\ m)}[/tex]
v = 8.12 m/s
A proton travels through uniform magnetic and electric fields. The magnetic field is in the negative x direction and has a magnitude of 2.48 mT. At one instant the velocity of the proton is in the positive y direction and has a magnitude of 1840 m/s. At that instant, what is the magnitude of the net force acting on the proton if the electric field is (a) in the positive z direction and has a magnitude of 5.19 V/m, (b) in the negative z direction and has a magnitude of 5.19 V/m, and (c) in the positive x direction and has a magnitude of 5.19 V/m
Answer:
a) F = 15.6 10⁻¹⁹ k^ N, b) F = -1 10⁻¹⁹ k^ N,
c) F = (8.3 i^ + 73 k^) 10⁻¹⁹ N
Explanation:
In this exercise we calculate the magnetic and electric force separately.
Let's start by calculating the magnetic force
F_m = q v x B
where bold letters indicate vectors, the modulus of this expression is
F_m = q v B
the direction is given by the right hand rule, where the thumb points in the direction of velocity, the fingers are extended in the direction of the magnetic field and the palm is in the directional ne force if the charge is positive
let's calculate the magnitude
F_m = 1.6 10⁻¹⁹ 1840 2.48 10⁻³
F_m = 7.3 10⁻¹⁹ N
we calculate the direction, the thumb is in the direction of + y,
fingers extended in the direction of -ax
the palm remains + z
therefore the magnetic force is in the direction of the positive side of the z axis
The electric force is
F_e = q E
give several possibilities for the electric field
a) electric field E = 5.19 V / m in the direction of + z
we calculate
F_e = 1.6 10⁻¹⁹ 5.19
F_e = 8.3 10⁻¹⁹ N
the total force is
F = F_m + F_e
F = (8.3 k ^ + 7.3 k ^) 10⁻¹⁹
F = 15.6 10⁻¹⁹ k^ N
b) in the -z direction
F_e = -8.3 10⁻¹⁹ k^ N
F = Fm + Fe
F = (-8.3 k ^ + 7.3 k ^) 10⁻¹⁹
F = -1 10⁻¹⁹ k^ N
c) in the + x direction
F_e = 8.3 10⁻¹⁹ i^ N
the total force is
F = (8.3 i^ + 73 k^) 10⁻¹⁹ N
Can someone please help me with science.
On the dog's return trip (between t = 10 and t = 12.5 seconds), the slope of the position function is steeper than during the first 5 seconds, which means the dog ran home faster. The only option that captures this is D.
You can check to make sure that the dog indeed runs twice as fast on the return trip. The slope of the position function during the first 5 seconds is
(change in position) / (change in time) = (5 - 0) / (5 - 0) = 5/5 = 1
while during the return trip, it is
(0 - 5) / (12.5 - 10) = -5/2.5 = -2
Ignoring the sign (which only indicates the direction in which the dog was running), we see that the dog's speed on the return trip was indeed twice as high as during the first 5 s.
takes 5 seconds and 2,000 J for a crane to lift a very heavy object. Which of these correctly describes power and energy for this action?
2,000 J of energy was converted into some other energy, requiring 10,000 W of power.
2,000 J of energy was converted into some other energy each second, requiring 400 W of power
2,000 J of power was converted into 400 W of energy.
2,000 J of power was converted into some other power every second, requiring 10,000 W of energy.
A crane takes 5 s and 2,000 J to lift an object. That is, 2,000 J of energy was converted into some other energy each second, requiring 400 W of power.
What is power?In physics, power is the amount of energy transferred or converted per unit time.
A crane uses 2,000 J of energy (E) to perform work (W) is 5 s (t). Let's calculate the power used (P).
P = W / t = 2,000 J / 5 s = 400 W
Which of these correctly describes power and energy for this action?
2,000 J of energy was converted into some other energy, requiring 10,000 W of power. No, the required power was 400 W.2,000 J of energy was converted into some other energy each second, requiring 400 W of power. Yes.2,000 J of power was converted into 400 W of energy. No, energy cannot be converted into power.2,000 J of power was converted into some other power every second, requiring 10,000 W of energy. No, the required power was 400 W.A crane takes 5 s and 2,000 J to lift an object. That is, 2,000 J of energy was converted into some other energy each second, requiring 400 W of power.
Learn more about power here: https://brainly.com/question/911620
#SPJ1
Suppose a blanket has a sock stuck to it due to static electricity. When you pull the sock off of the blanket, what happens to the potential energy between them?
Explanation:
When you pull the sock off of the blanket, the socks gain electrons out of blanket. This makes socks slightly negatively charged. The potential energy of the socks rise whereas potential energy of the blanket reduces. This happens because of exchange of electrons between socks and blanket.
A car hits a wall with a force of 80 N and
has a mass of 4.5 kg. What was the
acceleration of the car?
who won the 2020-2021 Nfl Mvp Award
Answer:
During a star-studded but socially safe ceremony for the 10th Annual NFL Honors, Green Bay Packers quarterback Aaron Rodgers earned the prestige of being the 2020 NFL Most Valuable Player (MVP).
a transfer of energy without a transfer of mass describes what?
Explanation:
Wave motion
ex...longitudinal wave.
Juan is studying a group of cells under a microscope. His teacher tells him that the cells either came from the leaf of a tomato plant or the scale of a lizard. Juan could conclude that the cells came from the tomato plant if they contained?
Answer:
chloroplasts
Explanation:
6. Sandy adds 3 sugar packets to her tea in order to make it sweeter. She stirs in the sugar and then takes a sip. She notices that not all the sugar was dissolved. What type of solution did she make?
A. Saturated B.Unsaturated C.Supersaturated D.Mildly saturated
Answer:
C.Supersaturated
Explanation:
There are three types of solution:
SATURATED SOLUTION:
It is the solution that contains maximum amount of solute dissolved in a solution in normal conditions.
UNSATURATED SOLUTION:
It is the solution that contains less than the maximum amount of solute dissolved in a solution in normal conditions. It has space for more solute to be dissolved in it.
SUPERSATURATED SOLUTION:
It contains more than the maximum amount of solute dissolved in it. Such a solution has no capacity to dissolve any more solute under any conditions.
Since the sugar is no more dissolving in the tea and has settled down. Therefore, the solution is:
C.Supersaturated
The equivalent resistance in a series circuit is found by ____
the resistances of all the resistors.
A. multiplying
B. comparing
C. adding the reciprocals of
D. adding
Explanation:
In a series circuit the equivalent resistance is the algebraic sum of the resistances.
If a body carries a charge of +3 C, then which of the following is true?
а) It has an excess of 4.8 x 10^19 electrons
b) It has an excess of 1.87 x 10^19 electrons *1019
C) It is deficit of 1.87 x 10^19 electrons
d) It is deficit of 4.8 x 10^19 electrons
Answer: C) it is deficit of 1.87 x 10^19 electrons
Explanation:
Seasons are more noticeable in places that are____from to the equator
Farther
Or
Closer
2.gravity and wind move water
True or false
It is for today pls help
PLEASE HELP!!!!!!!!!!!!!!!!Match the label with the reason it might be important to the consumers.
1. country of origin
Kelli only buys vegetables grown
without pesticides.
Angie only buys foods made with
2. Organic Certification
sea salt to cut sodium intake.
3. dietary guideline
Nikki prefers to buy local products
to lessen her carbon footprint.
Answer:
1 is Nikki
2 is Kelli
3 is Angie
Explanation:
Hope this helps!
What is the color of lava at its hottest? Help asap
Why must the Moon travel more than a full orbit around the Earth for the full moon to be complete?
Answer:
The difference between the sidereal and synodic months occurs becuase as our moon moves around the earth, the earth also moves around our sun. Our moon must travel a little farther in its path to make up for the added distance and complete the phase cycle.
Explanation:
Hope this helps.
Which of the following ways of writing 1000w is incorrect?
1) 1 kW
2) 1 x 10³ W
3) 10 x 10³ W
4) 1.0 x 10³ W
Answer:
the third one is incorrect
Explanation:
10 x 10³= 10^1 x 10^3 = 10^4
Please help please real quick
Answer:
1. (a) The final velocity is 20 m/s
(b) The distance travelled is20 meters
2. The distance travelled by the train in the 30 seconds is 825 meters
3. The most correct option is;
(d) 53 km
4. The heat, developed by the electric iron is 15,000 joules
5. a) In the first network the resistance between A and B is 2 Ω
b) In the second network the resistance between A and B is 4Ω
c) In the third network the resistance between A and B is 6Ω
d) In the fourth network the resistance between A and B is 2Ω
Explanation:
1. (a) The parameters of the cheetahs motion are;
The initial motion (velocity) of the cheetah = 0 m/s (The cheetah starts from rest)
The acceleration of the cheetah, a = 2 m/s²
The duration of the acceleration of the cheetah, t = 10 seconds
The kinematic equation of the motion of uniform acceleration, of the cheetah can be written in the following form;
v = u + a·t
s = u·t + 1/2·a·t²
Where;
v = The final velocity
u = The initial velocity = 0 m/s
a = The acceleration of the cheetah = 2 m/s²
s = The distance traveled
∴ v = 0 + 2 × 10 = 20
The final velocity, v = 20 m/s
(b) From s = u·t + 1/2·a·t², we have;
s = 0 × 10 + 1/2 × 10 × 2² = 20
The distance travelled, s = 20 meters
2. The given details of the motion of the train are;
The initial velocity of the train, u = 20 m·s⁻¹
The acceleration of the train, a = 0.5 m·s⁻²
The duration of the train's acceleration, t = 30 seconds
Therefore, the distance travelled, 's', is given by; s = u·t + 1/2·a·t²
∴ s = 20 × 30 + (1/2) × 0.5 × 30² = 825
The distance travelled by the train in the 30 seconds, s = 825 meters
3. The given distance the truck covers with the average speed of 80 km/h, d₁ = 40 km
The distance the truck then covers with the average speed of 40 km/h, d₂ = 40 km
[tex]Average \ speed = \dfrac{Total \ distance}{Time}[/tex]
[tex]\therefore time, \, t = \dfrac{Total \ distance}{Average \ speed}[/tex]
The time it takes the truck to cover the 40 km at 80 km/h = 40 km/(80 km·h) t₁ = 0.5 hour
The time it takes the truck to cover the 40 km at 80 km/h = 40 km/(40 km·h) t₂ = 1 hour
The total time taken to cover both 40 km distances, t = t₁ + t₂
∴ The total time taken to cover both 40 km distances, t = (0.5 + 1) hour = 1.5 hours
The total distance covered at both speeds, d = d₁ + d₂
∴ d = 40 km + 40 km = 80 km
The average speed of the truck for the total distance, [tex]v_{average}[/tex] = d/t
∴ [tex]v_{average}[/tex] = 80 km/1.5 hours = 53.[tex]\overline 3[/tex] km/h ≈ 53 km/h
The average speed of the truck for the total distance, [tex]v_{average}[/tex] ≈ 53 km/h
The correct option is (d) 53 km
4. The heat, 'H', developed by the electric iron is given by the following formula;
H = I²·R·t
Where;
I = The current flowing in the electric iron = 5 A
R = The resistance of the iron = 20Ω
t = The time duration of the flow of the current = 30 s
∴ H = (5 A)² × 20 Ω × 30 s = 15,000 joules
The heat, developed by the electric iron, H = 15,000 joules
5. Let 'R' represent the resistance between A and B in each network
a) For the first network, we have;
1/R = 1/(2 + 2) + 1/(2 + 2) = 1/4 + 1/4 = 1/2
∴ R = 2 Ω
∴ The resistance between A and B is 2 Ω
b) For the second network, we have;
R = 1/(1/2 + 1/2) + 3 = 4
R = 4Ω
∴ The resistance between A and B is 4 Ω
c) For the third network, we have;
R = 2 + 1/(1/4 + 1/4) + 2 = 6
R = 6Ω
∴ The resistance between A and B is 6 Ω
d) For the fourth network, we have;
R = 1/(1/2 + 1/2) + 1/(1/2 + 1/2) = 2
R = 2Ω
∴ The resistance between A and B is 2 Ω
Which material transmits the most visible light?
A.Sunglass lens
B.Mirror
C.Clear glass
D.Black cloth
Answer:
c
Explanation:
Find the tension in the two groups that are holding the 2.9 kg object in Pl., One makes an angle of 35.6° with respect to the vertical group 2 is pulling horizontally
Answer:
≈ 20.35 N [newton's of tension]
Explanation:
( (2.9 × 9.8) ÷ cos(35.6°) ) × sin (35.6°) =
( (28.42) ÷ (≈0.813) ) × (≈0.582) =
(≈34.96) × (≈0.582) = 20.3449446.... ≈ 20.35
Why is the magnetic force considered to be an action datance force
A Magnets in de bo exert a force
B. Magnets do not have to touch each other to experience a force.
C. Magnets push each other apan to increase the distance between them.
D Magnets mast be large in sire in onder to eden a force that is strong enough to notice
Which of the following statements is true about absolute zero?
It is the point at which electrons separate from the nucleus of atoms.
It is the point at which electrons separate from the nucleus of atoms.
It is theoretically the point at which all particle motion stops.
It is theoretically the point at which all particle motion stops.
It occurs at 273 degrees Kelvin.
It occurs at 273 degrees Kelvin.
It is the point at which protons separate from neutrons in the nucleus
Answer:
It is the point at which electrons separate from the nucleus of atoms. It is the point at which electrons separate from the nucleus of atoms. It is theoretically the point at which all particle motion stops. ... It occurs at 273 degrees Kelvin. ... It is the point at which protons separate from neutrons in the nucleus.
Explanation:
1. What is the magnitude of the force on a charge of +40 μC that is 0.6 m from a charge of - 80 μC?
Answer:
The magnitude of the force is 79.893 N.
Explanation:
The magnitude of the electrostatic force between the two particles is determined by Coloumb's Law, whose formula is:
[tex]F = \frac{\kappa \cdot |q_{A}|\cdot |q_{B}|}{r^{2}}[/tex] (1)
Where:
[tex]\kappa[/tex] - Electrostatic constant, in newtons-square meters per square coulomb.
[tex]q_{A}, q_{B}[/tex] - Electric charges, in coulombs.
[tex]r[/tex] - Distance, in meters.
If we know that [tex]\kappa = 8.988\times 10^{9}\,\frac{N\cdot m^{2}}{C^{2}}[/tex], [tex]q_{A} = +40\times 10^{-6}\, C[/tex], [tex]q_{B} = - 80\times 10^{-6}\, C[/tex] and [tex]r = 0.6\,m[/tex], then the magnitude of the force is:
[tex]F = \frac{\kappa \cdot |q_{A}|\cdot |q_{B}|}{r^{2}}[/tex]
[tex]F = 79.893\,N[/tex]
The magnitude of the force is 79.893 N.
Question 5 of 10
What are two things that happen when a home computer scanner uses
electromagnetic waves?
A. Red light shines on patterns of black and white, recording the
pattern of reflected light.
B. Objects are exposed to X-rays, which either pass through or are
absorbed by the objects.
C. A silicon chip releases electrons by the photoelectric effect,
producing an image.
D. A charge-coupled device captures visible light that is reflected off
an object
Answer: B. Objects are exposed to X-rays, which either pass through or are
absorbed by the objects.
C. A silicon chip releases electrons by the photoelectric effect,
producing an image.
Explanation:
WILL MAKE BRAINLIEST! How does Hooke’s law help us understand the force and energy in elastic materials?
Answer:
How does Hooke’s law help us understand the force and energy in elastic materials?:
When the elastic materials are stretched, the atoms and molecules deform until stress is been applied and when the stress is removed they return to their initial state
Explanation:
A car and a semi-truck are both traveling along a road. Based on Newton's 2nd law, what will happen if both cars apply the same type of brakes at the same time?
Answer: ask god in your prayers
Explanation: im here for the same reason you are
I DONT KNOW THE ANSWER
Answer:
The semi-truck will stop after the car.
Explanation:
It will do that because the semi-truck has more mass than the car.
Minh spent the weekend on his Wii and now has carpal tunnel syndrome. His 120 V outlet has an electrical current of 8A. What is the resistance in the Wii?
The resistance is 15 ohms.
Also, it's dissipating 960 watts whenever it's turned on. So it's almost as hot as a toaster, and Minh no longer has hands.
