Answer:
The police car is moving at 41.24 m/s.
Explanation:
To find the speed of the police car we need to use the Doppler equation:
[tex] f = f_{0}(\frac{v + v_{r}}{v + v_{s}}) [/tex]
Where:
v: is the speed of the sound = 343 m/s
[tex]v_{r}[/tex]: is the speed of the receiver = 12 m/s
[tex]v_{s}[/tex]: is the speed of the source =?
f: is the observed frequency = 959 Hz
f₀: is the emitted frequency = 1038 Hz
Both terms are positive in the fraction because the velocity of the sound is in the opposite direction to both velocities of the police car and the other car.
By solving the above equation for [tex]v_{s}[/tex] we have:
[tex] v_{s} = \frac{f_{0}(v + v_{r})}{f} - v = \frac{1038(343 + 12)}{959} - 343 = 41.24 m/s [/tex]
Therefore, the police car is moving at 41.24 m/s.
I hope it helps you!
A squash ball with an initial velocity of 19.21 m/s [W] is hit by a squash racket, changing its velocity to 40.22 m/s [E] in 0.312 s. What is the squash ball’s average acceleration?
Acceleration = (change in velocity) / (time for the change)
Change in velocity = 59.43 m/s East
Time for the change = 0.312 s
Acceleration = 190.5 m/s^2 East
PLSS HELPP
Are humans evolving? What will humans look like in 100,000 years in the future or longer?
Answer:
yes
Explanation:
An object is located 20.0 cm from a convex lens. The lens focuses light at a
distance of 10.0 cm. What is the image distance?
A. 6.67 cm
B. -6.67 cm
C. -20.0 cm
D. 20.0 cm
The Answer Is : D. 20.0 cm
My Reason : These types of problems can all be solved using the lens or mirror equation.
1/20 +1/q= 1/10
q=20 cm
The image is formed behind the lens at 2f or the center of curvature.
It is real, inverted, and the same size as the object
The Answer Is: D. 20.0 cm
Explanation: I did the test :)
Which type of map best shows the three dimensions of Earth’s surface?
Answer:
please give me brainlist and follow
Explanation:
topographic map
A topographic map shows a three-dimensional representation of a flat surface. It has contour lines joining points of equal elevation; the closer the lines are the steeper the elevation is.
A 5 kg ball is sitting on top of a hill. It has a Potential Energy of 6000J. What is the height of the ball?
Explanation:
mass=5 kg
potential energy=6000j
height=?
Now
potential energy =m.g.h
or 6000=5*9.8*h
or 6000=49h
or 6000÷49=h
or h= 122.45m
Waves that move through space are called
Answer:
Electromagnetic waves are waves that can travel through matter or through empty space
Light waves are
A.rotating waves.
B.longitudinal waves.
C.circular waves.
D.transverse waves
SHOCKING
Explanation:
Answer:
D i promises.
Explanation:
light waves can go 2 direction
Please Help Me!!!
Water is a colorless and odorless liquid. It can exist in solid, liquid, and gas states. It boils at 100 degrees C and melts at 0 degrees C.
Which option best describes this information?
A.
These are the physical properties of water.
B.
These are the chemical properties of water.
C.
These are the physical changes water undergoes.
D.
These are the chemical changes water undergoes.
E.
These are the molecular changes water undergoes.
Answer:
There are the molecular changes water undergoes
Two resistors, 2.50 Ω and 4.95 Ω, are wired in series to a 12.00 V battery. What is the equivalent resistance of the circuit?
Answer:
7.45 Ω
Explanation:
From the question given above, the following data were obtained:
Resistor 1 (R₁) = 2.50 Ω
Resistor 2 (R₂) = 4.95 Ω
Voltage (V) = 12 V
Equivalent Resistance (Rₑq) =?
Since the resistors are in series arrangement, the equivalent resistance can be obtained as follow:
Rₑq = R₁ + R₂
Rₑq = 2.5 + 4.95
Rₑq = 7.45 Ω
Therefore, the equivalent resistance is 7.45 Ω
Which material transmits the most visible light?
A.Sunglass lens
B.Mirror
C.Clear glass
D.Black cloth
Answer:
c
Explanation:
Blackie, a cat whose mass is 6-kg, is napping on top of the refrigerator when he rolls over and fall. Blackie has a KE of 90-J just before he lands on his feet on the floor.
How tall is the refrigerator?
To answer this question, you need to understand the law of conservation of energy. Essentially, the law states that energy cannot be created or destroyed; it is always conserved.
Knowing this law, how can we answer this question? Well, let's look at what the question tells us. We know that Blackie was initially at the top of a refrigerator before rolling over and falling to the ground. At ground level, he only has Kinetic energy when he lands. Since we know that he started at the top of the fridge, we know that Blackie started off with potential gravitational energy.
That would make sense, right? Written out as an equation, it'd be:
[tex]U_{g}[/tex] = [tex]K_{E}[/tex]
This follows the law of conservation of energy, as all the potential gravitational energy is converted into Kinetic energy.
Now, we know what energies are converted. What can we do with it? Recall the equation of potential gravitational energy:
[tex]U_{g}[/tex] = [tex]F_{g}[/tex]∆H
[tex]U_{g}[/tex] = mg∆H
Do you see it now? ∆H is the distance that Blackie falls, and since Blackie jumps from the fridge to the ground, ∆H must be the height of the fridge!
Let's start solving for ∆H:
[tex]U_{g}[/tex] = [tex]K_{E}[/tex]
Substitute potential gravitational energy with our equation:
mg∆H = [tex]K_{E}[/tex]
We were given the value of Kinetic Energy:
mg∆H = 90
Isolate ∆H by dividing both sides by mg:
∆H = [tex]\frac{90}{mg}[/tex]
Input values for 'm' and 'g' (m is the mass of Blackie and g is Earth's acceleration)
∆H = [tex]\frac{90}{6*9.80}[/tex]
∆H = [tex]\frac{90}{58.8}[/tex]
∆H = 1.53
The refrigerator is 1.53 meters tall.
And that's it! Let me know if you need me to explain anything I did here.
- breezyツ
The _____________ variable is observed, measured, and affected by the independent variable.
Answer: It would be the dependent variable.
Explanation:
The dependent variable is limited and can be affected by the changes and manipulation of the independent variable.
how fossils influence and change our understanding of the history of Earth and it's species.
Answer:
Fossils are the preserved remains or traces of animals, plants, and other organisms from the past. Fossils are important evidence for evolution because they show that life on earth was once different from life found on earth today.
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:
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 ME I AM TIMED!
Answer:
Well my good friend the other person did not give U a good answer, it is actually the third one
Explanation: well it is the most logical of all the answers if you think about it and a lot of the creatures we have in the water today are thought of to have once lived on land based on the fossils we still find to this very day my friend
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:
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
Three people push a piano on wheels with forces of 130 N to the right, 150 N to the left, and 165 N to the right. What is the strength and direction of the net force on the piano?
Answer:
45 N to the right possibly?
A 100 L ball is blown up inside at 200K. It is then taken outside in the hot sun, and the volume increases to 150 L. What is the new temperature?
Answer:
Temperature, T2 = 300 Kelvin
Explanation:
Given the following data;
Initial volume = 100 Liters
Initial temperature = 200 Kelvin
Final volume = 150 Liters
To find the final temperature T2, we would use Charles' law.
Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.
Mathematically, Charles is given by;
[tex] \frac {V}{T} = K[/tex]
[tex] \frac{V1}{T1} = \frac{V2}{T2}[/tex]
Making T2 as the subject formula, we have;
[tex] T_{2}= \frac{V_{2}}{V_{1}} * T_{1}[/tex]
Substituting into the formula, we have;
[tex] T_{2}= \frac{150}{100} * 200[/tex]
[tex] T_{2}= 1.5 * 200 [/tex]
Temperature, T2 = 300 Kelvin
What do you call the shot that starts on the right side and continues through to the left
side for a right handed player?
Answer:
When a right-handed golfer’s tee shot curves to far to the left, the shot is described as a “hook.” This shot typically occurs when the club head moves across the ball from left to right, imparting side-spin on the ball
Define the types of friction and give FOUR examples of each
Static Friction
Rolling Friction
Sliding Friction
Fluid Friction
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 car travels 9 km East, turns around, then travels 3 km West. What is the car's
DISPLACEMENT? *
Explanation:
I think you are 100℅ clear.
A flute plays a note with a frequency of 266Hz. What is the speed of sound if the wavelength is 1.3m?
Explanation:
Wave speed = (frequency) x (wavelength)
= (266 /sec) x (1.3 meters)
PLEASE ANSWER THIS ASAP I WILL MARK YOU THE BRAINLIEST The actual subject is Science but they dont have that as a option in pick a subject
Answer:
The average speed for the runner B for the first 25 seconds was;
30/25 = 1.2 m/s
Explanation:
The average speed of an object is given by the following formula
[tex]Average \ speed = \dfrac{Total \ distance \ covered}{Total \ time \ taken \ to \ cover \ the \ distance}[/tex]
From the graph, we have;
The coordinates of the runner B at the start = (0, 0)
The coordinates of the runner B after 25 seconds = (25, 30)
The total distance covered by the runner B after 25 seconds = The difference between the position at 25 seconds and the origin which is 30 meters
∴ The total distance covered by the runner B after 25 seconds = 30 meters
The time it takes the runner B to cover the distance = The 25 seconds
[tex]\therefore \ For \ the \ runner \ B, the \ average \ speed = \dfrac{30 \ meters}{25 \ seconds} = 1.2 \ m/s[/tex]
The average speed for the runner B for the first 25 seconds = 30 m/(25 s) = 1.2 m/s.
A 2.5m long steel piano wire has a diameter of 0.5cm how great is the tention in the wire if it stretches by 0.45cm when tightened taking the young's modulus to be 2.0×10^11 N/m^2
Answer: Their u go i found it their was about 3 pages i did not no what pages u had to do.
Explanation:
GIVING BRAINLIEST PLEASE HELP!!
-if you answer correctly ill give you brainliest which will give you 23pts-
Answer:
B is the answer!!
Explanation:
If all the forces acting on an object are balanced then the net force acting on it is zero. True or, false?
Answer:
true
Explanation:
if all forces are equal then there would be no stronger force to give any net force so it would be zero
The half-life of technetium-99 is 6 hours.How much of a 100 milligram sample of
technetium-99 will remain after 30 hours? *
O 3.125 mg
O 12.5 mg
O 6.25 mg
O 1.56 mg
