Answer:
C. lever
Explanation:
Any sort of prying tool is an example of a lever.
Answer:
A lever
Explanation:
A cheetah can start from rest and attain the velocity 72km/h in 2 seconds. Calculate the acceleration of cheetah.
Answer:
Acceleration(a)=21.60 km/h or 21,600 m/s
Explanation:
Since you have the initial velocity(0, because it starts from rest) and the final velocity 72 km/h or 72,000 m/s. so...
[tex]a=\frac{Vf-Vi}{t}\\ a=\frac{72,000 m/s-0}{2s}\\ a=\frac{72,000 m/s}{2s}\\ a=36,000m/s or 36 km/h[/tex]
Barry walks from one end to the other of a 30-meter long moving walkway at a constant rate in 30 seconds, assisted by the walkway. When he reaches the end, he reverses direction and continue walking with the same speed, but this time it takes him 120 seconds because he is traveling against the direction of the moving walkway. If the walkway were to stop moving, how many seconds would it take Barry to walk from one end of the walkway to the other
Answer:
Δt=48 s
Explanation:
v: Barry's speed
v.: speed of the walkway
Δx=30 m
Δt1=30 s , Δt2=120 s
|Δx1|=|Δx2|
Δx=v*Δt
=> (v+v.)*30=(v-v.)*120
v=v.*5/3
30=(v+v.)*30
=> 30=(5v./3 +v.)*30
v.=3/8 m/s
v=5v./3 , v.=3/8
=> v=5/8 m/s
Δx=v*Δt
30=5/8 *Δt
Δt=48 s
Suppose that the sound level of a conversation is initially at an angry 71 dB and then drops to a soothing 54 dB. Assuming that the frequency of the sound is 504 Hz, determine the (a) initial and (b) final sound intensities and the (c) initial and (d) final sound wave amplitudes. Assume the speed of sound is 346 m/s and the air density is 1.21 kg/m3.
Answer:
Explanation:
In the decibel scale , intensity of sound changes logarithmically as follows
[tex]10log\frac{I}{I_0} =[/tex] Value in decibel scale , the value of I₀ = 10⁻¹² W /m².
Putting the values
[tex]10log\frac{I}{10^{-12}} = 71[/tex]
[tex]log\frac{I}{10^{-12}} = 7.1[/tex]
[tex]\frac{I}{10^{-12}} = 10^{7.1}[/tex]
[tex]I= 10^{-4.9}[/tex] W/m²
Similarly for 54 dB sound intensity can be given as follows
I = 10⁻¹² x [tex]10^{5.4}[/tex]
[tex]I= 10^{-6.6 }[/tex] W / m²
For intensity of sound the relation is as follows
I = 2π²υ²A²ρc where υ is frequency , A is amplitude , ρ is density of air and c is velocity of sound .
Putting the given values for 71 dB
[tex]I= 10^{-4.9}[/tex] = 2π² x 504²xA²x 1.21 x 346
A² = 60.03 x 10⁻¹⁶
A = 7.74 x 10⁻⁸ m
For 54 dB sound
[tex]10^{-6.6}[/tex] = 2π² x 504²xA²x 1.21 x 346
A² = 1.1978 x 10⁻¹⁶
A = 1.1 x 10⁻⁸ m
An angular frequency wave ω0 has an average power P0. If your angular frequency increases by 20%, find the percentage by which its power increases.
Answer:
44%
Explanation:
The average power of a wave is directly proportional to the square of the frequency.
P ∝ ω²
Writing a proportion:
P₁ / P₀ = ω₁² / ω₀²
P₁ / P₀ = (1.2 ω₀)² / ω₀²
P₁ / P₀ = 1.44
P₁ = 1.44 P₀
The power increases by 44%.
Define centre of gravity and centre of Bouyancy
Answer:
Center of Gravity is the point in a body where the gravitational force may be taken to act. Center of Buoyancy is the center of gravity for the volume of water which a hull displaces.
(blank)a0 is undeniably accepted by scientists all over the world as the primary language of science.
Answer:
English.
Explanation:
English is undeniably accepted by scientists all over the world as the primary language of science. It is a language spoken all over the world and is also the language of science because it is an official language and can be understood by almost everyone.
Answer:
[tex]\boxed{\mathrm{English}}[/tex]
Explanation:
English is undeniably accepted by scientists all over the world as the primary language of science. The scientific methods and experiments are done by communicating and writing in English. Scientists use English to communicate and share knowledge as English is understood by people from around the world.
please help me with this
Answer:
12 Ω
Explanation:
Data obtained from the question include:
Resistor 1 (R1) = 50 Ω.
Resistor 2 (R1) = 30 Ω.
Resistor 3 (R3) = 20 Ω.
Resistor 4 (R4) = R
Galvanometer reading = Zero deflection.
The Resistor 4 (R4) in the Wheatstone bridge can be obtained as follow:
Since the galvanometer gives zero deflection, it means the bridge is balanced. Therefore,
R1/R2 = R3/R4
50/30 = 20/R
Cross multiply
50 x R = 30 x 20
Divide both side by 50
R = (30 x 20)/50
R = 12 Ω
Therefore, the value of R in the wheatstone bridge is 12 Ω.
Earthquakes at fault lines in Earth's crust create seismic waves, which are longitudinal (P-waves) or transverse (S-waves). The P-waves have a speed of about 9 km/s. Estimate the average bulk modulus of Earth's crust given that the density of rock is about 2500 kg/m3
Answer:
[tex]B=2.025\times 10^{11}\ Pa[/tex]
Explanation:
It is given that,
Speed of P- waves, v = 9 km/s = 9000 m/s
The density of rock is about [tex]2500\ kg/m^3[/tex]
We need to find the average bulk modulus of Earth's crust. Let it is given by B. So,
[tex]v=\sqrt{\dfrac{B}{d}} \\\\B=v^2d\\\\B=(9000)^2\times 2500\\\\B=2.025\times 10^{11}\ Pa[/tex]
So, the bulk modulus of the Earth's crust is [tex]2.025\times 10^{11}\ Pa[/tex].
The water tank is kept at some height of the buildings. Why?
Answer:
The water is at the top because when the water is stored at the top it does not need as much energy to get it to flow because it will be flowing down and be affected by gravity to make the water pressure.
Answer:
The water is at the top because when the water is stored at the top it does not need as much energy to get it to flow because it will be flowing down and be affected by gravity to make the water pressure.
Explanation:
A horizontal spring with spring constant 210 Nm is compressed by 20 cm and then used to launch a 250 g box across the floor. The coefficient of kinetic friction between the box and the floor is 0.23. What is the box's launch speed?
Answer:
ugmd = 1/2 kx²
d = (1/2 kx²) / (ugm)
= (1/2 * 250 N/m * (0.2 m)²) / (0.23 * 9.81 m/s² * 0.3 kg)
= 7.4 m
ugmd = 1/2 mv²
v = √2ugd
= √(2(0.23)(9.81 m/s²)(7.4 m)
= 5.8 m/s
Explanation:
The box's launch speed is 5.8 m/s.
What is energy?Energy is the ability or capability to do tasks, such as the ability to move an item (of a certain mass) by exerting force. Energy can exist in many different forms, including electrical, mechanical, chemical, thermal, or nuclear, and it can change its form.
Given in question spring with spring constant 210 Nm is compressed by 20 cm and then used to launch a 250 g box across the floor,
ugmd = 1/2 kx²
d = (1/2 kx²) / (ugm)
= (1/2 * 250 N/m * (0.2 m)²) / (0.23 * 9.81 m/s² * 0.3 kg)
= 7.4 m
ugmd = 1/2 mv²
v = √2ugd
= √(2(0.23)(9.81 m/s²)(7.4 m)
= 5.8 m/s
The box's launch speed is 5.8 m/s.
To learn more about energy refer to the link:
brainly.com/question/1932868
#SPJ5
To get an idea how big a farad is, suppose you want to make a 1.0-F air-filled parallel-plate capacitor for a circuit you are building. To make it a reasonable size, suppose you limit the plate area to 1.4 cm2 .
Part A
What would the gap have to be between the plates?
Express your answer using two significant figures and include the appropriate units.
Part B
Is this practically achievable?
Is this practically achievable?
a. yes
b. no
Answer:
The gap between the plates will be 1.2 x 10^-15 m
No, this is not practically achievable.
Explanation:
Capacitance = 1.0 F
area of plate = 1.4 cm^2 = 1.4/10000 m^2 = m^2
distance = ?
We use the equation
[tex]C[/tex] = [tex]\frac{A}{d}[/tex]*ε
C is the capacitance
where A is the area
d is the distance of separation of plates
ε is the permeability of free space = 8.854×10^-12 F⋅m−1
substituting values, we have
1 = [tex]\frac{0.00014}{d}[/tex]* 8.854×10^-12
distance between plates = 1.2 x 10^-15 m
This is not practically achievable in real life
Why does time seem to flow only in one direction?
Answer:
Time seem to flow only in one direction because if it started to go in backward direction that would break the second law of thermodynamics. We do not find time to be moving in any direction because time is not an object that can move nor is it a force that can move any object.
(a) In electron-volts, how much work does an ideal battery with a 17.0 V emf do on an electron that passes through the battery from the positive to the negative terminal? (b) If 3.88 × 1018 electrons pass through each second, what is the power of the battery?
Answer:
(a) 17.0eV
(b) 10.55W
Explanation:
(a) The amount of work done (W) on an electron by an ideal battery of emf value of V as it moves from the positive to the negative terminal is given by;
W = q x V --------(i)
Where;
q = charge on the electron = 1e
From the question;
V = 17.0 V
Substitute the values of q and V into equation (i) as follows;
W = 1e x 17.0
W = 17.0eV
Therefore, the work done in electron volts is 17.0
(b) The power (P) of the battery as some electrons (n) pass through it at time t, is given as;
P = (n q V) / t --------------(ii)
Where;
n = number of electrons = 3.88 x 10¹⁸
t = 1s
q = 1.6 x 10⁻¹⁹C
V = 17.0V
Substitute these values into equation (ii) as follows;
P = (3.88 x 10¹⁸ x 1.6 x 10⁻¹⁹ x 17.0) / 1
P = 10.55W
Therefore the power of the battery is 10.55W
A train travels 120 km at a speed of 60 km/h, makes a stop for 0.5 h, and then travels the next 180 km at a speed of 90 km/h. What is the average speed of the train for this trip? 9th grade level pls FFFFFFFFFFFAAAAAAAAAAASSSSSSSSSSSSSTTTTTTTTTTTTT
Answer:
average speed = 66.67 km/h
Explanation:
In order to find the average speed of the train, you need to calculate the total distance traveled, divided by the time it took to cover that distance. So for the total distance:
Distance= 120 km + 180 km = 300 km
For the total time we need to add three different quantities, two of which we need to derived based on the information provided:
time for first part of the trip:
[tex]time_1=\frac{D_1}{v_1} =\frac{120}{60} \,h= 2\,h[/tex]
for the time of the stop:
[tex]time_2=0.5\,\,h[/tex]
for the last part of the trip:
[tex]time_3=\frac{180}{90} \,h= 2 \,\,h[/tex]
Which gives a total of 4.5 hours
Then, the average speed is: 300/4.5 km/h = 66.67 km/h
A spherical mirror gives an image magnified 5 times at a distance 5 m. determine whether the mirror is convex or concave? How much will be the focal length of the mirror?
Answer:
1. Concave mirror.
2. 4.17 m or 417 cm.
Explanation:
The following data were obtained from the question:
Object distance (u) = 5 m
Magnification (M) = 5
Focal length (f) =..?
1. Identification of the mirror.
To determine whether or not the mirror is concave or convex, we must first of all calculate the image distance.
This can be obtained as follow:
Object distance (u) = 5 m
Magnification (M) = 5
Image distance (v) =.?
Magnification (M) = image distance (v) /object distance (u).
M = v/u
5 = v/5
Cross multiply
v = 5 x 5
v = 25 m
Since the image distance obtained is positive, the mirror is said to be a concave mirror.
2. Determination of the focal length of the mirro.
This can be obtained as follow:
Object distance (u) = 5 m
Image distance (v) = 25 m
Focal length (f) =...?
1/f = 1/v + 1/u
1/f = 1/25 + 1/5
1/f = 0.04 + 0.2
1/f = 0.24
Cross multiply
f x 0.24 = 1
Divide both side by 0.24
f = 1/0.24
f = 4.17 m
Converting the focal length of cm, we have:
1 m = 100 cm
Therefore, 4.17 m = 4.17 x 100 = 417 cm
Therefore, the focal length of the mirror is 4.17 or 417 cm.
Determine whether or not each of the following statements is true. If a statement is true, prove it. If a statement is false, provide a counterexample and explain how it constitutes a counter-example.
A capacitor consists of two flat, metal plates with unequal areas. Each of the plates starts neutral, and then each plate is connected to a dierent terminal of a battery. After some time, the plates will have excess charge on them, and the magnitude of the excess charge on one plate will equal the magnitude of the excess charge on the other plate.
A. True
B. False
If a wire carries current, then it has a net non-zero charge in it.
A. True
B. False
Answer:
a) True b) True
Explanation:
a) a capacitor is made up of two flat plates and each one has a charge of the same sign, therefore the statement is true
b) the current is the flow of electrons per unit of time, therefore the charge is not zero, therefore the statement is True
Theere is more role of the moon than sun to occur tides in oceans why?
Help
Answer:
Because ocean tides are the effect of ocean water responding to a gravitational gradient, the moon plays a larger role in creating tides than does the sun. But the sun's gravitational gradient across the earth is significant and it does contribute to tides as well.
i hope this help i
i try to explain and like i sayed i hope this help u.
Answer:
the moon
Explanation:
ive passed the grade you learned this in
4.
An "extreme" pogo stick utilizes a spring whose uncompressed length is 46 cm and whose force constant is 1.4 x 104 N/m. A 60-kg person is jumping on the pogo stick,
compressing the spring to a length of only 5.0 cm at the bottom of their jump. Which is the upward acceleration of the person at the moment the spring reaches its greatest
compression at the bottom of their jump?
6 m 2
Answer:
a = 85.9 m / s²
Explanation:
For this exercise we can use Newton's second law in the most compressed part
F - W = m a
force is the spring elastic force
F = - k Δx
k Δx - m g = m a
a = k/m Δx - g
Δx = x₀ -[tex]x_{f}[/tex]
ΔX = 46 - 5 = 41cm (1m / 100cm) = 0.41 m
let's calculate
a = 1.4 10⁴/60 0.41 - 9.8
a = 85.9 m / s²
WILL MARK AS BRAINLIEST...,.. A constant force vector f =2i cap+3j cap-5k cap acts on a particle and displaces it from (1,2,-3) m to (2,5,-1) m. find the work done by the force .
Explanation:
Given that,
Force, [tex]F=2i+3j-5k[/tex]
The particle displaces from (1,2,-3) m to (2,5,-1) m.
We need to find the work done by the force. Work done by the force is given by :
W = Fd
It is equal to the dot product of force and displacement.
Displacement from (1,2,-3) m to (2,5,-1) m is (2-1, 5-2, -1-(-3)) or (1, 3, 2) m
Work done,
[tex]W=F{\cdot} d\\\\W=(2i+3j-5k){\cdot} (i+3j+2k)[/tex]
We know that, i.i=j.j=k.k=1
So,
[tex]W=1\ J[/tex]
So, the work done by the force is 1 J.
When a constant force acts upon an object, the acceleration of the object varies inversely with its mass. When a certain constant force acts upon an object with mass , the acceleration of the object is . If the same force acts upon another object whose mass is , what is this object's acceleration 19 4 2
Answer:
The acceleration of the object is 4 m/s².
Explanation:
When a constant force acts upon an object, the acceleration of the object varies inversely with its mass i.e.
[tex]a=\dfrac{k}{m}[/tex] ...(1)
Let us assume that the question is a certain force acting upon an object with mass 2 kg produces an acceleration of 38 m/s². if the same force acts upon another object whose mass is 19 kg, what would this object's acceleration be
Equation (1) can be written as :
[tex]\dfrac{a_1}{a_2}=\dfrac{m_2}{m_1}[/tex]
Here,
a₁ = 38 m/s², a₂ =?, m₁ = 2 kg, m₂ = 19 kg
So,
[tex]\dfrac{38}{a_2}=\dfrac{19}{2}\\\\a_2=4\ m/s^2[/tex]
So, the acceleration of the object is 4 m/s².
Velocity is a description of an object’s blank
Velocity is the description of an object's motion from one point to another.
It tells the speed with which the trip is completed, and the direction from the start-point to the end-point. It tells nothing about any twists, turns, loops, bends, or stops along the way.
HELP!?
Convert 107 km/h into m/s.
Answer: 29.72
Explanation:
you multiply the number by 5 then divide by 18=
107x5= 535
535/18= 29.72
what is the electric force between two points charges when q1=-4e, q2 = +3e, and r = 0.05 m?
Answer:
Option A. 1.1×10¯²⁴ N
Explanation:
The following data were obtained from the question:
Charge 1 (q1) = - 4e
Charge 2 (q2) = + 3e
Distance apart (r) = 0.05 m
Electric field constant (K) = 9×10⁹ N•m²/C²
Electron (e) = 1.6×10¯¹⁹ C.
Electric Force (F) =..?
Next, we shall determine the value of the two charges.
This is illustrated below:
Charge 1 (q1) = - 4e
Charge 1 (- q1) = 4e
Electron (e) = 1.6×10¯¹⁹ C.
Charge 1 (- q1) = 4 × 1.6×10¯¹⁹ C.
Charge 1 (- q1) = 6.4×10¯¹⁹ C.
Charge 2 (q2) = + 3e
Electron (e) = 1.6×10¯¹⁹ C.
Charge 2 (q2) = 3 × 1.6×10¯¹⁹ C.
Charge 2 (q2) = 4.8×10¯¹⁹ C.
Finally, we shall determine the value of the electric force. This can be obtained as shown below:
Charge 1 (- q1) = 6.4×10¯¹⁹ C.
Charge 2 (q2) = 4.8×10¯¹⁹ C.
Electric field constant (K) = 9×10⁹ N•m²/C².
Distance apart (r) = 0.05 m
Electric Force (F) =..?
F = Kq1q2 /r²
F = (9×10⁹× 6.4×10¯¹⁹× 4.8×10¯¹⁹)/(0.05)²
F = 1.1×10¯²⁴ N
Therefore, the electric force between the two point charge is 1.1×10¯²⁴ N
Magnetic field lines form closed loops:________.
a) Around and through bar magnets.
b) Through current-carrying loops.
c) Around current-carrying straight wires.
d) All of the above.
Answer:
d) All of the above.
Explanation:
Magnetic field lines are formed around an object when there is a magnetic field around the object. From the question, we know that a bar magnet has an electric field. A current carrying loop has a magnetic field around it also. Current carrying straight wires and any conductor generally, carrying an electric current, produces a magnetic field around them. This magnetic field has lines of loos formed close to the material.
Research have found that other than for reasons of hunger, American women eat when they are depressed ,whereas Japanese women eat because of social demands.They found no significant differences between american and japanese men. These results demonstrate that ________ and _______ must be taken into account when studying why and under what circumstances people eat.
Answer:
culture
food
Explanation:
The above mentioned studied the interaction between food and culture. Food habits reflect different meanings in different cultures. As per the question, the United States America and Japan are two countries far away from each other, which have distinct cultures and gave rise to different eating norms. However, the impact of media have been shaping the eating patterns around the globe, which have brought different food and cultures together.
An arrow is launched from P with a speed Vi = 25m / s. Knowing that the target Q is 10 m high, and the arrow reaches it as shown in the figure, we are asked to determine the distance X. (g = 10m / s2).
Answer:
20 m
Explanation:
Given in the y direction:
Δy = 10 m
v₀ = 25 m/s sin 37° = 15.0 m/s
a = -10 m/s²
Find: t
Δy = v₀ t + ½ at²
10 m = (15.0 m/s) t + ½ (-10 m/s²) t²
10 = 15t − 5t²
2 = 3t − t²
t² − 3t + 2 = 0
(t − 1) (t − 2) = 0
t = 1 or 2
Since the projectile reaches Q before it reaches the peak, we want the lesser time, so t = 1.
Given in the x direction:
v₀ = 25 m/s cos 37° = 20.0 m/s
a = 0 m/s²
t = 1 s
Find: Δx
Δx = v₀ t + ½ at²
Δx = (20.0 m/s) (1 s) + ½ (0 m/s²) (1 s)²
Δx = 20 m
A wire carrying a 35.0 A current passes between the poles of a strong magnet such that the wire is perpendicular to the magnet's field, and there is a 2.55 N force on the 3.00 cm of wire in the field. What is the average field strength (in T) between the poles of the magnet
Answer:
7.65 T
Explanation:
From the question,
Using,
F = BILsinФ......................... Equation 1
Where F = Force, B = magnetic field strength, I = current, L = Length, Ф = Angle.
Make B the subject of the equation
B = F/ILsinФ........................Equation 2
Given: F = 2.55 N, I = 32 A, L = 3.00 cm = 0.03 m, Ф = 90° (perpendicular)
Substitute into equation 2
B = 2.55/(32×0.03×sin90°)
B = 2.55/0.96
B = 7.65 T
3. Assume that each atom of copper contributes one free electron. The density of Cu is 9g/cc and atomic weight is 63g. if the current flowing through the copper wire of 1mm dia is 1.1A, drift velocity of electrons will be-
Answer:
[tex]v_d=0.1\ mm/s[/tex]
Explanation:
The current flowing through a conductor is given as:
[tex]I=neAv_d\\where\ A =area\ of\ conductor=\pi d^2/4=\pi(1*10^-3)^2/4=7.85*10^{-7}\\\\I=current\ flowing\ through\ the \ conductor=1.1A\\\\e=charge\ of \ electron=1.602*10^{-19}\\\\N_A=Avogadro \ constant=6.023*10^{23}\ mol^{-1}\\\\Density=9*10^3kg/m^3=9*10^6g/m^3\\\\n=\frac{6.023*10^{23}\ mol^{-1}*9*10^6\ g/m^3}{63\ g/mol} =8.604*10^{28}\ m^{3}\\\\v_d=\frac{I}{neA}=\frac{1.1}{8.604*10^{28}*1.602*10^{-19}*7.85*10^{-7}}=0.0001\ m/s\\\\v_d=0.1\ mm/s[/tex]
Choose the correct answer/s
refer to the attachment for the explanation
A car drives at a constant speed of 21 m/s around a circle of radius 100 m.
What is the centripetal acceleration of the car?
O A. 4.8 m/s2
O B. 0.21 m/s2
O C. 3.1 m/s2
O D. 4.4 m/s2
Answer:
Option D. 4.4 m/s²
Explanation:
The following data were obtained from the question:
Velocity (v) = 21 m/s
Radius (r) = 100 m
Centripetal acceleration (a) =.?
The centripetal acceleration of the car can be obtained as follow:
Centripetal acceleration (a) = Velocity square (v²) / radius (r)
a = v²/r
a = 21²/100
a = 441/100
a = 4.41 ≈ 4.4 m/s²
Therefore, the centripetal acceleration of the car is 4.4 m/s².