A ball of mass .5 kg is dropped from rest from a height of 7 meters. What is its speed just before it hits the ground.
Answer:
Explanation:
Kinematic equation: Final velocity^2 = Initial velocity^2 + 2*acceleration*displacement
As the ball is dropped from rest, initial velocity = 0.
Acceleration = gravity = 9.8m/s^2
Displacement = 7m
So velocity just before it hits ground
= sqrt( 2*9.8*7)
= 11.71m/s
A 18Ω resistance is cut into three equal parts and connected in parallel. Find the equivalent resistance of the combination.
Answer:
2Ω
Explanation:
If a 18Ω resistance is cut into three equal parts each of the resistance will be 18Ω/3 = 6Ω
Equivalent ratio in parallel is expressed as:
1/R = 1/6 + 1/6 + 1/6
1/R = 3/6
Cross multiply
3R = 6
R = 6/3
R = 2Ω
Hence the required equivalent resistance is 2Ω
8. A 22 g bullet with a speed of 230 m/s is fired in to a tree and comes to rest 23 cm into
the tree
a) Find the work done by the tree to stop the bullet
b) Find the average force exerted by the tree
Answer:
kinetic energy of 16 J. Determine the velocity of the first toy, and the mass of the ... distance of 12 cm into the tree. ... b) the average force exerted on the bullet while slowing down to a stop.
14 pages·317 KB
I just... I don't know man I suck at physics :(
A tour guide shouts across a canyon. At a temperature of 20 °C, her echo is heard 2.00 s later. How wide is the canyon?
The answer is 340 m I just don't know how to get that....
Explanation:
Sound travels from the tour guide to the other of the canyon and then back, thus hearing the echo. The time of 2.0 s represents the time it takes the sound to make a round trip, therefore it takes 1.0 s for the tour guide's voice to reach the other side of the canyon. At 20°C, the speed of sound is 343 m/s therefore the width of the canyon is
[tex]x = vt = (343\:m/s)(1.0\:s) = 343\:m[/tex]
The canyon in the given question is 340 m wide.
What is echo?Echo is a reflection of sound that comes to the listener after the direct sound, but with a delay. The delay is inversely proportional to the separation between the source and the listener of the reflecting surface.
To hear the echo, the following conditions must be met:
There must be a minimum of 17 meters between the sound source and the reflecting surface, and there must be at least 0.1 seconds between the original sound and its echo.
Given parameters:
When a tour guide shouts across a canyon, her echo is heard 2.00 s later. That means, in two seconds the sound goes to other wall of canyon and reflected back.
At a temperature of 20 °C, velocity of sound is 340 m/s.
So, the wide is the canyon be = velocity of sound × time/2
= 340 m/s ×2 s/2s = 340 m.
Hence, the wide is the canyon be 340 m.
Learn more about echo here:
https://brainly.com/question/26833784
#SPJ2
which is a standard unit of measurement
HELP ME PLEASE I NEED IT NOW
a) What is the value of the angle of incidence of Ray PQ on the mirror AB?
Answer:
the angle of incident is 40°
Explanation:
NQ is the normal to the mirror, therefore
angle NQA =90°
PQA = 50°
incident angle = NQA - PQA
90°- 50° = 40°
note that the angle of reflection is equal to the angle of incident
Which variable is represented by the following symbol? λ
a. Wavelength
b. Amplitude
c. Frequency
d. Velocity
Answer:
A
Explanation:
Wavelength is represented by lambda
Calculate the kinetic energy of a car of mass 800kg moving at 100 kmph.
Answer:
KE = 308642.02469136 J
What is velocity and it’s SI Unit?
Answer:
Velocity is the displacement (change In position of an an object it is similar to distance ) divided by the time taken. SI unit m/s (metre per second)
Question 4: Mac and Tosh stand 8 meters apart and demonstrate the motion of a
transverse wave on a string. The wave can be described as having a vertical
distance of 32 cm from a trough to a crest, a frequency of 2.4 Hz, and a
horizontal distance of 48 cm from a crest to the nearest trough. Determine the
amplitude, wavelength, and speed of such a wave. Show all of your work and
explain your steps for solving the problem
Answer:
Explanation:
Refer to the pic below that I attached as we talk through these answers.
The amplitude is shown as the height from the top of one wave (called the crest) to the midline. If the whole vertical height from crest to trough is 32 cm, then the amplitude is half of that at
A = 16 cm
The wavelength, or λ, is the horizontal distance from crest to crest or trough to trough. Therefore, our wavelength is 48 cm + 48 cm which is
λ = 96 cm
The speed of the wave is the same thing as the velocity of the wave which can be found in the equation
[tex]f=\frac{v}{\lambda}[/tex] where f is the frequency of the wave and lambda is the wavelength. Filling in:
[tex]2.4=\frac{v}{96}[/tex] and
2.4(96) = v so
v = 230 m/s to the correct number of sig fig's
which material has more specific heat?
Answer:
SO
Explanation:
SI
Answer:
Explanation:
dynamic equilibrium
A dog accelerates at 1.50 m/s^2 to reach a velocity of 13.5 m/s while covering a distance of 49.3 m. What was his initial velocity?
A) 34.4 m/s
B) 5.86 m/s
C) 18.2 m/s
D) 330. m/s
Answer:
Explanation:
The equation you need for this is a one-dimensional:
[tex]v_f^2=v_0^2 +2a[/tex]Δx (sorry that looks weird. It is all one equation, even though it's "crooked"!)
We have final velocity, acceleration, and the displacement, and we are looking for initial velocity. I see after working this out that you don't use the die-hard rules for significant digits, so I adapted to get an answer that matches exactly what one of your choices is. Filling in:
[tex](13.5)^2=v_0^2+2(.50)(49.3)[/tex] and
[tex](13.5)^2-2(1.50)(49.3)=v_0^2[/tex] and
[tex]\sqrt{(13.5)^2-2(1.50)(49.3)}=v_0[/tex] so
v₀ = 5.86 m/s
help please!! will give brainly for full answers
1) Many detaches the two wires from the battery and reattaches them to the opposite terminals. Explain how this changes the current and magnetic field.
2) Suppose you pull the paperclips away from the nail. Explain how the potential energy between the paperclips and the nail changes.
A man on a beach notices that four waves arrive on the shore every 20 seconds. What is the frequency of the waves?
Answer:
0.2 Hz
Explanation:
Frequency: This can be defined as the number of circles completed by a wave in one seconds. The s.i unit is hertz.
From the question,
If 4 Waves arrives on the shore every 20 seconds,
Then,
x waves will arrives on the shore in one seconds
Solving for x
x = (4×1)/20
x = 0.2 Hz
Hence the frequency of the wave is 0.2 Hz
An object is placed closer to the lens than f for a diverging lens. The image will be located:
a) between f and 2f
b) between the lens and f
c) A or B or C
d) farther than 2f
A carpenter applies a force of 60N horizontally to push a plane 40 cm along a piece of wood, how much work does she do?
Answer:
W = 24 J
Explanation:
Given that,
Applied force, F = 60 N
Distance moved, d = 40 cm = 0.4 m
We need to find the work done by the carpenter. We know that,
Work done, W = Fd
Put all the values,
W = 60 N × 0.4 m
= 24 J
Hence, the required work done is equal to 24 J.
The metal wire in an incandescent lightbulb glows when the lights is switch on and stops glowing when switched off. This simple process is which kind of a change?
Answer:
When the metal wire in an incandescent lightbulb glows when the light is switched on and stops glowing when it is switched off, this is an example of resistance, which provides light and heat.
Explanation:
Opening or closing a circuit.
lol i'm going to fail please help
Scientists have found that the long slow sound produced by blue whales is almost consistently a B pitch at 16.0 Hz. The wavelength of this note is 97.5 m. How long would it take for this sound from a blue whale of scientists that is tracking them from 11 km away?
The answer is 7.1 s I just don't know how to get it :/
NO LINKS ISTGGGG
Answer:
Explanation:
The frequency is 16.0 Hz. That means that 16 of these waves can pass a single point in 1 second. We are given frequency and wavelength. The equation that relates them is
[tex]f=\frac{v}{\lambda}[/tex] where f is frequency, v is velocity, and λ is wavelength. Putting all this together:
[tex]16.0=\frac{v}{97.5}[/tex] and solving for velocity,
v = 16.0(97.5) so
v = 1560 m/s. This wave can travel 1560 meters in a single second!!! Now that we know this velocity, we can use it in a proportion to find our unknown, which is how long, t, it will take to hear this sound 11000m away. (11 km is 11000m):
[tex]\frac{1560m}{1s}=\frac{11000}{t}[/tex] and cross multiply to get
1560t = 11000 so
t = 7.1 seconds
Which of the following describes the work done by a heat engine?
A. Qin - Qout
B. Qin - W
C. Qout - Qin D. Qin + Qout
Answer: A.
Explanation:
Máquina térmica tem como função, manter a temperatura de um dado fluído, então, a quantidade de calor desse mesmo fluído ao entrar na máquina, será igual á quantidade de calor desse fluido saindo.
Qin - Qout describes the work done by a heat engine. Hence option A is correct.
What is heat engine ?A heat engine is a system which converts heat into useful work. Carnot engine is an ideal engine which has maximum efficiency than any other engines. Carnot has showed that "no engine can be more efficient than Carnot engine and the 100% efficient engine can not be existed". It takes heat from the reservoir to do some work and it discharges some amount of heat to the sink. Reservoir is know as hot body and sink is know as cold body.
Efficiency of the Carnot's heat engine is given by,
Efficiency, η = Work done / Heat input
Work done, W = Q1 – Q2
Heat input = Q1
Efficiency,
η = W / Q1
= (Q1 – Q2) / Q1
=1 – (Q2 / Q1).
To have engine with 100% efficiency, Q2 must be zero and it is not possible.
Hence work done by a heat engine is Qin - Qout.
To know more about heat engine, click :
https://brainly.com/question/28034387
#SPJ7.
(a) You wish to determine the height of the smokestack of a local coal burning power plant. You convince a member of the maintenance crew to mount the support for a simple pendulum at the top of the stack and you suspend a 1.00 kg mass that just misses the ground at its lowest point from the pendulum cord. If the period of the pendulum is 18.7 s, determine the height of the smokestack. 8455.69 Incorrect: Your answer is incorrect. What factors influence the period of a simple pendulum
Answer:
a. 86.80 m
b. i. The mass of the bob
ii. The length of the pendulum
Explanation:
a. Determine the height of the smokestack.
Using T = 2π√(L/g) where T = period of pendulum = 18.7 s, L = length of pendulum = height of smokestack and g = acceleration due to gravity = 9.8 m/s².
So, making L subject of the formula, we have
T = 2π√(L/g)
T/2π = √(L/g)
squaring both sides, we have
(T/2π)² = L/g
L = (T/2π)²g
Substituting the values of the variables into the equation, we have
L = (T/2π)²g
L = (18.7 s/2π)²(9.8 m/s²)
L = (2.976 s)²(9.8 m/s²)
L = 8.857 s² × 9.8 m/s²
L = 86.796 m
L ≅ 86.80 m
b. What factors influence the period of a simple pendulum
The factors that influence the period of a simple pendulum are
i. The mass of the bob
ii. The length of the pendulum
Consider this equation,
KE = ½ mv2
Which of those variables is changing as the skater moves up and down the track?
Answer:
V is changing
[tex]as \: skater \: moves : \: there \: is \: displacement \\ from \: third \: equation \: of \: motion \\ {v}^{2} = {u}^{2} + 2as \\ {( \delta \: V})^{2} = 2as \\ V \: \alpha \: s[/tex]
If a 2.0Ω resistor and a 4.0Ω resistor are connected with a 12 volt battery, what is the total resistance of the circuit?
4.8Ω
9.2Ω
6.0Ω
1.3Ω
Which is NOT a characteristic of a solid?
a) All solids have a definite shape.
b) All solids have molecules that are loosely packed together.
C) All solids have mass.
d) All solids take up space
Answer:
b
Explanation:
Calculate the electric potential at point A, the middle of the rectangle, and at point B, the middle of the right-hand side of the rectangle. How would you find the electric potential?
Answer:
With the help of formula.
Explanation:
We can calculate the electric potential of any point through the formula of electric potential which is given below.
Electric potential = Coulomb constant x charge/ distance of separation.
Symbolically it can be written as, V = k q/ r where
V = electric potential
k = Coulomb constant
q = charge
r = distance of separation
If we have all these data, we can simply put the data in the formula and we will get the value of electric potential.
A radio station transmitted a radio wave with frequency of 25MHz the value of the frequency is equivalent to? *
Question
A radio station transmitted a radio wave with frequency of 25MHz the value of the frequency is equivalent to? Leave answer in Hz and in standard form.
Answer:
2.5 x 10⁷Hz
Explanation:
The measured frequency is 25MHz
To convert this to Hz, we simply change the M, which means mega, to its equivalent value which is 10⁶.
Therefore, we have;
25MHz = 25(10⁶) Hz
=> 25MHz = 25 x 10⁶ Hz
Now express this value in standard form as follows;
25 x 10⁶ Hz = 2.5 x 10¹ x 10⁶
=> 25 x 10⁶ Hz = 2.5 x 10⁷ Hz
Therefore, the value of 25MHz is equivalent to 2.5 x 10⁷Hz
The value of the frequency of the radio wave is equivalent to 2.5 × 10⁷ Hertz.
Given the data in the question;
Frequency of radio wave; [tex]f = 25MHz[/tex]
Frequency is the number of occurrences of a repeating event per unit of time. The SI unit for frequency is the hertz (Hz)
We know that;
[tex]1MHz\ ( Megahertz) = 1000000 Hz\ ( Hertz )[/tex]
so
[tex]25MHz = x[/tex]
We cross multiply
[tex]x = \frac{25MHz\ *\ 1000000Hz}{1MHz} \\\\x = 2.5 * 10^7 Hz[/tex]
Therefore, the value of the frequency of the radio wave is equivalent to 2.5 × 10⁷ Hertz.
Learn more: https://brainly.com/question/67787
the quantum theory of radiation reflects:
the principle of superposition
the electromagnetic theory of light
the special theory of relativity
the principle of the photoelectric effect
Answer:
The electromagnetic theory of light , that's the answer
Answer:
the electromagnetic theory of light
Explanation:
got it right on o.w
16) A man ran a 5 mile race. The race looped around a city park and back
to the starting line. What is the man's total displacement? *
Answer:
The man's total displacement is equal to 0.
Explanation:
Given that,
A man ran a 5 mile race. The race looped around a city park and back to the starting line.
We need to find the total displacement of the man.
We know that,
Displacement = shortest path covered
Also,
Displacement = final position - initial position
As it reaches back to its starting line, it means, the displacement is equal to 0.
Hence, the man's total displacement is equal to 0.
Una persona pesa 700 N al nivel del mar. ¿Cuándo sube a un avión a
10000 m de altura pesará más, igual o menos? Bien explicado por favor
Answer:
The weight of the person decreases.
Explanation:
Weight of person at sea level = 700 N
height = 10000m
We know that the weight is given by product of mass and the acceleration due to gravity.
The acceleration due to gravity at height is given by
[tex]g' =g\times \left ( \frac{R}{R+h} \right )^2[/tex]
Where, R is the radius of earth and h is the height.
Now, as we go on heights , the acceleration due to gravity decreases, so the weight also decreases as we go on heights.
Someone HELP if the displacement is in the start and it ends in the same spot then would It be 0?
Answer:
Yes
Explanation:
Displacement is equal to the final position of X minus the initial position of X.
A student is in class 400 minutes every day for 5 days each week. How many seconds is this?
Answer:
120,000seconds
Explanation:
400 minutes x 5= 2000minutes (2000minutes x 60)seconds =120,000seconds.
btw :
stay safe! :3
Answer:
12000
Explanation:
5 x 400 = 2000, 2000 x 60 = 12000