Answer:
B 5s
Explanation:
Because of the Displacement in the nth second of the free fall is
Snth=21g(t12−t22)
Given that (tn−tn−1)=1
Displacement in 3 seconds of the free fall
S=21gt2
S=21×10×32
S=45m
Given that: Snth=45
On solving that we get:
t1=5sec
b) Calculate the equivalent capacitance of the network shown below between the points A nd 'B', Given: C1 = C2 = 12uF.C3 = 7uF, CA = C5 = C6 =151F C6 =15uF
As No diagram attached I am taking all are connected in series
We know
[tex]\boxed{\sf C_{eq}=C_1+C_2\dots}[/tex]
[tex]\\ \sf \longmapsto C_{eq}=12+12+7+15+15+15[/tex]
[tex]\\ \sf \longmapsto C_{eq}=24+7+45[/tex]
[tex]\\ \sf \longmapsto C_{eq}=76\mu F[/tex]
A roller coaster has a total track length of 500 yards. A complete ride on the roller coaster is considered two times around the track. The start and stop places for the ride are virtually the same. What are the distance and displacement for a ride on the roller coaster? Explain your answers.
Answer:
Explanation:
its 1000 yards if its going around the track 2 times and that if one whole around the track is 500 its 500 x 2
A student has a large number of coins of different diameters, all made of the same metal. She wishes to find the density of the metal by a method involving placing the coins in water.
a) State the formula needed to calculate the density.
b) Describe how the measurements of the required quantities are carried out.
Answer:
a)density = mass /volume
b)to find volume put water into a container .measure the level of water , put the coins into the beaker containing water , measure the level of water again, subtract the new volume withe the first one . the result is the volume of coins
Which nucleus complete the following equation
(C) [tex]^{208}_{84}\text{Po}[/tex]
Explanation:
[tex]^{212}_{86}\text{Rn} \rightarrow \:^4_2\text{He} + \:^{208}_{84}\text{Po}[/tex]
We do not use water instead of mercury in a barometer
Answer:
Because
1)Water is relatively less dense. Mercury is 13.6 times more dense than water. SO, If you use water, you have to have the length of barometer of length (or height) 13.534 times the length of mercury barometer, which may be more than 11 meter in length.
2)Also mercury as compared to water, has comparatively less specific heat and good conductor of heat, could come to the same temperature of the atmosphere more quickly.
Answer:
The atmospheric pressure at sea level 76 cm of Hg=1.013× 10⁵ pascal .
Explanation:
That is if water is used in barometer tube instead of mercury the length of the tube must be greater than 10.326 cm.so we cannot replace mercury by water in the barometer.
Megan accelerates her skateboard from 0 m/s to 8 m/s in 2 seconds. What is the magnitude of the acceleration of the skateboard?
O 8 m/s^2
O 16 m/s^2
O 2 m/s^2
O 4 m/s^2
Answer:
chk picture for eqn
Explanation:
Open the sash half way up, take the beaker containing the dry ice / water out of the hood, and slowly move it from right in front of the hood all the way down to the floor. At what point do the fumes stop getting sucked up by the fume hood?
Answer:
The fumes stop getting sucked up by the fume hood once the beaker is pulled out of the hood.
Which circuit has the larger equivalent resistance: a circuit with two 10 ohm resistors connected in parallel or a circuit with two 10 ohm resistors connected in series?
Answer:
A circuit with two 10 ohm resistors connected in series.
Explanation:
The formula for the equivalent resistance for resistors in parallel is
[tex]\frac{1}{Rt} = \frac{1}{R1} + \frac{1}{R2}[/tex] So if R1=R2= 10 [tex]\frac{1}{Rt} = \frac{1}{10} + \frac{1}{10} = \frac{2}{10} <=> Rt =\frac{10}{2} =5 ohm[/tex]
The formula for the equivalent resistance for resistors in series is
Rt = R1 + R2 So Rt= 10 + 10 = 20
A car is running with the velocity of 72 km per hour what will be its velocity after 5 seconds if its acceleration is -2 metre per second square
Answer:
initial velocity (u)=72×1000/60×60
=72000/3600
=20m/s
final velocity(v)=v
Time(t)=5s
acceleration(a)=-2m/s
now,
acceleration(a)=v-u/t
-2=v-20/5
-2×5=v-20
-10=v-20
-10+20=v
v=10m/s
Define simple harmonic motion. Write down the expressions for the velocity and aceraletion of such motion st different position along its path
Answer:
Simple harmonic motion is a special type of periodic motion or oscillation motion where the restoring force is directly proportional to the displacement and acts in the direction opposite to that of displacemen
Two resistors connected in series have an equivalent resistance of 690 Ohms. When they are connected in parallel, their equivalent resistance is 118 Ohms. Find the resistance of each resistor.
Explanation:
Let [tex]R_1[/tex] and [tex]R_2[/tex] be the the resistances of the resistors. We are given that
[tex]R_1 + R_2 = 690\:Ω\:\:\:\:\:\:\:(1)[/tex]
and
[tex]\dfrac{1}{R_1} + \dfrac{1}{R_2} = \dfrac{1}{118\:Ω}\:\:\:\:\:(2)[/tex]
From Eqn(1), we can write
[tex]R_2 = 690\:Ω - R_1[/tex]
and then plug this into Eqn(2):
[tex]\dfrac{1}{R_1} + \dfrac{1}{690\:Ω - R_1} = \dfrac{1}{118\:Ω}[/tex]
or
[tex]\dfrac{690\:Ω}{(690\:Ω)R_1 - R_1^2}= \dfrac{1}{118\:Ω}[/tex]
[tex]\Rightarrow R_1^2 - (690\:Ω)R_1 + (690\:Ω)(118\:Ω)= 0[/tex]
or
[tex]R_1^2 - 690R_1 + 81420 = 0[/tex]
Using the quadratic formula, we find that the above equation has two roots:
[tex]R_1 = 151.1\:Ω,\:\:538.9\:Ω[/tex]
This means that if you choose one root value for [tex]R_1[/tex], the other root will be the value for [tex]R_2[/tex].
Which of the units of the following physical quantities are derived
Answer:
where is the attachment
Explanation:
how is the area of a circle measured
Answer:
Area of circle is measured using formula πr² which means π×radius×radius and π could be 22/7 or 3.14
Explanation:
If you like my answer than please mark me brainliest
A bicyclist moves along a straight line with an initial velocity vo and slows downs. Which of the following the best describes the signs set for the initial position, initial velocity and the acceleration ?
The sign set after the slowdown of the bicycle will be positive for the position, negative for velocity, and negative for acceleration.
What is velocity?The rate at which an object's position changes when observed from a specific point of view and when measured against a specific unit of time is known as its velocity.
According to Que, when a bicyclist moves in a straight line and slows down, then the velocity decrease as displacement is decreasing, and the acceleration also decreases only displacement increases.
Therefore, the sign set for the position is +ve, for velocity it is -ve, and for acceleration also -ve
To know more about Velocity:
https://brainly.com/question/19979064
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A biker slows down after traveling in a long, straight line at initial velocity v0. Which of the following the best \sdescribes the signs set for the initial position, initial velocity and the acceleration? Initial position Initial velocity Acceleration
A. Positive Negative Negative
B. Positive Positive Negative
C. Negative Positive Negative
D. Negative Negative Positive
E. Negative Negative Negative
The “rainbow” surface of a CD or DVD is the result of a transmission grating.
True
or
False
The “rainbow” surface of a CD or DVD being the result of a transmission grating is False.
What is Reflection grating?This happens when white light reflects on a metal to give rainbow colors and interesting patterns.
This is seen on the surface of a CD which is why transmission grating being the cause is false.
Read more about Reflection here https://brainly.com/question/26494295
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a dentist used a light have wavelength 450nm what is the energy of the light
Answer:
≈ 4.41 x 10^-19
Explanation:
The formula for the energy of light is...
E = hc / λ
where 'h' is Planck's constant: 6.626 x 10^-34 Js
'c' is the speed of light: 2.998 x 10^8 ms
& 'λ' is the wavelength (in this case): 450 nm
1 nanometer (nm) = 1 x 10^-9m
E = (6.626 x 10^-34 Js)(2.998 x 10^8 ms) / (450nm)(1 m / 10^-9 nm)
E ≈ 4.41 x 10^-19 J
I think that's the answer and I hope it helps!
If you jump off a 5 m diving platform how long will take you hit the water
Answer:
t = 1.0s
Explanation:
^d = v_0*t + (1/2)*a*t²
(5m-0m) = 0m/s*t + (.5)(9.81m/s²)*(t)²
5m = (4.905m/s²)*t²
t² = 1.01937s²
t = √1.01937s²
t = 1.0s
The first law of motion describes the principle of __________
Answer:
The first law of motion describes the principle of law of inertia.
A sound wave made up of large number of unrelated frequencies superposted on each other is
Since the frequencies are unrelated, and there are a large number of them, I'll say this represents an example of noise.
Why does cold water kept in an open container become warm on a hot summer afternoon?
Cold water kept in an open container acquires heat from the warmer surrounding becomes warm like the air around it due to the transfer of thermal energy
Pls mark as brainliest
The source of sound moves away from the listener.The listener has the impression that the source is lower in pitch. Why?
When the source is moving away from the observer the velocity of the source is added to the speed of light. This increases the value of the denominator, decreasing the value of the observed frequency. Frequency corresponds to pitch or tone; a lower observed frequency will result in a lower observed pitch.
The armature of an AC generator has 200 turns, which are rectangular loops measuring 5 cm by 10 cm. The generator has a sinusoidal voltage output with an amplitude of 18 V. If the magnetic field of the generator is 300 mT, with what frequency does the armature turn
Answer:
[tex]f=9.55Hz[/tex]
Explanation:
From the question we are told that:
Number of Turns [tex]N=200[/tex]
Length [tex]l=5cm to 10cm[/tex]
Voltage [tex]V=18V[/tex]
Magnetic field [tex]B=300mT[/tex]
Generally, the equation for Frequncy of an amarture is mathematically given by
[tex]f =\frac{ V}{(N B A * 2 pi )}[/tex]
[tex]f =\frac{ 18}{(200 300*10^{-3} (10*10^-2)(5*10^{-2}) * 2 *3.142 )}[/tex]
[tex]f=9.55Hz[/tex]
please i dont understand
elastic wire extend by 1.ocm when a load on 20g range from It, what additional load will it be required Cause the futher extension of 2.0cm
Answer:
40g
Explanation:
20g range > 1.0cm
Therefore,
40g range > 2.0cm
Which of the units of the following physical quantities are derived
Answer:
You have not provided options but so long as the option is none of these, it's the right answer:
Electric current, Thermodynamic temperature,mass,time amount of substance,length, luminous intensity
Determine the point of contraflexure
Answer:
The point of contraflexure (PoC) occurs where bending is zero and at the point of change between positive and negative (or between compression and tension). In a beam that is flexing (or bending), the point where there is zero bending moment is called the point of contraflexure.
For example, we can take Water
In (A) Water has same mass and great volume
In (B) Water has same mass and lower volume
Will there be any change in its density then?
Answer:
yes there will be change in its density
what is a main difference between local units and standard units?
Explanation:
local units doesn't give accurate measurement
but standard units give accurate measurement
Light of wavelength 600 nm illuminates a diffraction grating. The second-order maximum is at angle 39.2. How many lines per millimeter does this grating have?
Answer:
Diffraction equation applies in this case:
d*Sin x = m*wavelength, where d = spacing of lines, x = angle = 39.5°, m = order of maximum = 2
Substituting;
d* Sin 39.5 = 2*600*10^-9
d = (2*600*10^-9)/Sin 39.5 = 1.88656*10^-6 m
In 1 mm (or 0.001 m), the number of lines is given as;
Number of lines = 0.001/d = 0.001/(1.88656*10^-6) = 530.065 ≈ 530 lines
A 80 kg bungee jumper is on a bridge that is 100 meters above a river. Attached to the jumper is a bungee cord that is 50 meters long. After jumping off of the bridge, the jumper reaches a position that is 10 meters above the river when the bungee cord is at its maximum stretch.
Required:
a. How much energy is stored in the bungee cord at that maximum stretch?
b. What is the spring force constant of the bungee cord?
Answer:
a) 70,560 J
b) 88.2 N/m
Explanation:
The spring potential will equal the change in gravity potential
PS = PE = mgh = 80(9.8)(100 - 10) = 70,560 J
PS = ½kx²
k = 2PS/x² = 2(70560)/(100 - 50 - 10)² = 88.2 N/m
