Answer:
80 m or 81.3 m
Explanation:
Initially it had no velocity(as at rest). Let the height be h
Using conservation of energy:
Initial KE + PE = final KE + PE
(1/2) m(0)² + mgh = (1/2) m(40)² + mg(0)
mgh = (1/2) m (1600)
2gh = 16000
h = 1600/(2*10) {for g = 10}
h = 80
80 For g = 9.8, h = 81.3 m
Using Newton's eqⁿ of motion:
v² = u² + 2aS
40² = 0² + 2(g)S
1600/2g = S
For g = 10, S = 80 m
g = 9.8, S = 81.33 m
The Doppler Effect is caused by which of the following?
Select all that apply…
A - motion of the source
B - the type of wave
C - original frequency of the source
D - motion of the observer
E - type of medium the wave is in
Answer:
the type of wave
Explanation:
Description: Doppler Effect works on both light and sound objects. For instance, when a sound object moves towards you, the frequency of the sound waves increases, leading to a higher pitch. Conversely, if it moves away from you, the frequency of the sound waves decreases and the pitch comes down.
I have an unknown volume of gas at a pressure of 0.500 atm and a temperature of 325 K. If I raise the pressure to 1.20 atm, decrease the temperature to 320. K, and measure the final volume to be 48.0 liters, what was the initial volume of the gas?
Answer:
117
Explanation:
the formula is P1V1 over T1 is equals to P2V2 over T2
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 :)
1.
David is 10% taller than Peter and Peter is 5% shorter than John. It is given that the height of Peter
is 171 cm.
(a) Find the height of John.
Iso
(2 marks)
(b) David claims that he is the tallest person among the three. Do you agree? Explain your answer.
(2 marks)
Answer:
I don't know if I can help you with that
Does the eruption from a volcano represent force
Answer:
Yes, because of the force of gas exploding the volcano from pressure is a force.
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.
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
A meter is larger than a
A.
hectometer
B.
kilometer
C.
decimeter
D.
dekameter
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
GIVING BRAINLIEST PLEASE HELP!!
-if you answer correctly ill give you brainliest which will give you 23pts-
Answer:
B is the answer!!
Explanation:
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
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?
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
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
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)
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:
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
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
PLSS HELPP
Are humans evolving? What will humans look like in 100,000 years in the future or longer?
Answer:
yes
Explanation:
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
Which of the following scenarios would result in an increase of kinetic
energy?*
A) An object at rest at a height of 10 meters
B) A car accelerating from 10 m/s to 20 m/s
C) A car coming to a stop
Answer:
B) A car accelerating from 10 m/s to 20 m/s
Explanation:
I explained this yesterday.
Give 1 real life example of a scenario that takes advantage of the inverse relationship between force and time when impulse is constant. Describe how it is an example of impulse and how force and time are involved.
Answer:
On real life example of a scenario that takes advantage of the inverse relationship between force and time when impulse is constant is when making a serve with a lawn tennis racket
How It is an example of impulse is that when a serve is made by moving the bat slowly, the lawn tennis player uses less force and the ball is in contact with the string for longer a period
When however, the lawn tennis player moves the racket faster, with the strings of the racket highly tensioned he uses more force and the ball also spends less time on the racket to produce the same momentum
Explanation:
The impulse of a force, ΔP is given by the following formula;
ΔP = F × Δt
Where ΔP is constant, we have;
F ∝ 1/Δt
Therefore, for the same impulse, when the force is increased, the time of contact is decreases and vice versa.
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.
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
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
Waves that move through space are called
Answer:
Electromagnetic waves are waves that can travel through matter or through empty space
Define the types of friction and give FOUR examples of each
Static Friction
Rolling Friction
Sliding Friction
Fluid Friction
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:
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
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.
