Answer:
Explanation:
The mass of that science book...wow. In pounds that would be 35.2! Yikes!
Anyway, we need final velocity here, and the mass of the book has nothing to do with how fast it falls. Everything is pulled by the same gravity. A feather falls at 9.8 m/s/s and so does an elephant. Mass is useless information. The equation we will use is
[tex]v^2=v_0^2+2a[/tex]Δx where
v is the final velocity, our unknown,
v₀ is the initial velocity which is 0 since someone had to be holding the book before dropping it,
a is the pull of gravity which is always -9.8 m/s/s, and
Δx = -120 which is the displacement (it's negative because the book falls below the point from which it was dropped). Filling in:
[tex]v^2=0^2+2(-9.8)(-120)[/tex] so
[tex]v=\sqrt{2(-9.8)(-120)}[/tex] and
v = 48 m/s
As far as how far above the bottom of the cliff the object is when it is moving at 12 m/s we will use the same equation, but the velocity will be 12:
[tex]12^2=0^2+2(-9.8)[/tex]Δx and
144 = -19.6Δx so
Δx = -7.3 m. That's how far from the top of the cliff it is. We subtract then t find out how far it is from the bottom:
120 - 7.3 = 112.7 m off the ground.
The moon Phobos orbits Mars
(mass = 6.42 x 1023 kg) at a distance
of 9.38 x 106 m. What is its period of
orbit?
Answer:
The moon Phobos orbits Mars (m = 6.42 x 1023 kg) at a distance of 9.38 x 106 m.
A 47.2 kg girl is standing on a 177 kg plank. The plank, originally at rest, is free to slide on a frozen lake, which is a flat, frictionless surface. The girl begins to walk along the plank at a constant velocity of 1.53 m/s relative to the plank. What is her velocity relative to the ice surface
Answer:
v_g,i = 1.208 m/s
Explanation:
We are given;
Mass of girl; m_g = 47.2 kg
Mass of plank; m_p = 177 kg
Let the velocity of girl to ice be v_g,i
Let the velocity of plank to ice be v_p,i
Since the velocity of the girl is 1.53 m/s relative to the plank, then;
v_g,i + v_p,i = 1.53
From conservation of momentum;
m_g × v_g,i = m_p × v_p,i
Thus;
47.2(v_g,i) = 177(v_p,i)
Dividing both sides by 47.2 gives;
v_g,i = 3.75(v_p,i)
v_pi = (v_g,i)/3.75
Thus, from v_g,i + v_p,i = 1.53, we have;
v_g,i + ((v_g,i)/3.75) = 1.53
v_g,i(1 + 1/3.75) = 1.53
1.267v_g,i = 1.53
v_g,i = 1.53/1.267
v_g,i = 1.208 m/s
You have a simple pendulum that oscillates with a period of 2 s as you stand on the surface of Earth. Your friend, an astronaut standing on the surface of the Moon, has a pendulum of the same length. What would be the period of oscillation of your friend’s pendulum?
a. Less than 2 s
b. The answer depends on whether the amplitudes are the same
c. More than 2 s
d. Exactly 2 s
Answer:
c. More than 2 s
Explanation:
First, we will find the length of the pendulum:
[tex]T = 2\pi \sqrt{\frac{l}{g}}\\\\2\ s = 2\pi \sqrt{\frac{l}{9.81\ m/s^2}}\\\\4\ s^2 = 4\pi^2 (\frac{l}{9.81\ m/s^2})\\\\l = \frac{(4\ s^2)(9.81\ m/s^2)}{4\pi^2} \\\\l = 0.99\ m[/tex]
Now, the value of g becomes 1.625 m/s² on the surface of the moon. So the time period will be:
[tex]T = 2\pi \sqrt{\frac{l}{g}}\\\\T = 2\pi \sqrt{\frac{0.99\ m}{1.625\ m/s^2}}\\\\[/tex]
T = 4.9 s
Therefore, the correct option is:
c. More than 2 s
4. Water stands 12.0 m deep in a storage tank whose top is open to the atmosphere at
1.00 atm. The density of water is given as 1000 kg/m² and some pressure conversion
are 1 Pa = 1 N/m² while 1 atm = 101 325 Pa.
a) What is the absolute pressure at the bottom of the tank?
b) What is the gauge pressure at the bottom of the tank?
[4]
[4]
Answer:
[tex]P=217600Pa[/tex]
Explanation:
From the question we are told that:
Density [tex]\rho=1000kg/m^3[/tex]
Depth of Water [tex]d=12.0m[/tex]
Generally the equation for Pressure is mathematically given by
[tex]P=\rho gh[/tex]
[tex]P=1000*9.8*12[/tex]
[tex]P=117600N/m^2[/tex]
Therefore
Absolute Pressure=P+P'
Where
P=Pressure under water
P'=Atmospheric Pressure
Therefore
[tex]P_A=P+P'[/tex]
[tex]P_A=117,600+10^5[/tex]
[tex]P=217600Pa[/tex]
A bucket of mass m in a well is held up by a rope. the rope is wound around a drum of radius r there is also a handle of length R attached to the drum. the tension in the rope is equal to T. If the buket is allowed to fall into the well, which point will have the greatest angular acceleration, a point on the rim of the drum (at radius r) or a point on the end of the handle (at radius R)?
a. The point on the rim of the drum.
b. The point at the end of the handle.
c. They will both have the same angular acceleration.
Answer:
the correct answer is C
Explanation:
This is a system with circular motion, there is a relationship between the linear and angular variables
a = α r
with the cube going down the well, the tension of the leather is maintained therefore the acceleration of the cube is
W = m a
-mg = ma
a = -g
this acceleration a is the same as that at the edge of the drum.
α = a / r
where we can see that the angular acceleration is constant
consequently the correct answer is C
Directions: Use the universal law of gravitation to calculate the acceleration due to gravity on different planets
Planet
Mass = KG
Radius = M
Force experienced by 75kg astronaut
Acceleration due to Gravity
Mercury
3.3x1023 kg
2.439x106 m
Venus
4.87x1024 kg
6.052x106 m
Earth
5.972x1024 kg
6.378x106 m
Mars
6.417x1023 kg
3.389x106 m
Jupiter
1.899x1027 kg
6.991x107 m
Saturn
5.685x1026 kg
5.823x107 m
Uranus
8.682x1025 kg
2.536x107 m
Neptune
1.024x1026 kg
2.462x107 m
Answer:
5gbyb5hn6 kub5yyb6hb5 Hi hi7ki6mh4yutyimimy mjymyjmjyhnttbr
To accurately describe the wind, the measurement should include
A) a direction, but not a speed
B)a speed, but not a direction
C) both a speed and a direction
D) neither a speed nor a direction
Answer:
C. both a speed and a direction
If a force of 50 N stretches a spring 0.40 m, what is the spring constant?
Answer:
The spring constant = 125 N/m
Explanation:
Given that :
Force = 50 N
distance (x) = 0.40 m
Recall that, From Hooke's law
Force = kx
where;
k = spring constant.
∴
50 N = k × 0.40 m
k = 50 N/0.40m
k = 125 N/m
The sound from a trumpet radiates uniformly in all directions in 20C air. At a distance of 5.00 m from the trumpet the sound intensity level is 52.0 dB. The frequency is 587 Hz. (a) What is the pressure amplitude at this distance
Answer:
The answer is below
Explanation:
The intensity level (B) of a sound wave is given by:
B = 10log(I/I₀);
where I₀ is the threshold intensity = 1 * 10⁻¹² W/m², I is the intensity at distance 5 m, B is the intensity level = 52 dB
Substituting gives:
[tex]52=10log(\frac{I}{10^{-12}} )\\\\log(\frac{I}{10^{-12}} )=5.2\\\\I=1.58*10^{-7}\ W/m^2[/tex]
The pressure is given by:
[tex]I=\frac{p_{max}^2}{2\rho v} \\\\\rho=air\ density=1.2\ kg/m^3,v=speed\ of\ sound\ in\ air=344\ m/s,p_{max}=pressure:\\\\p_{max}=\sqrt{2\rho vI}=\sqrt{2*1.58*10^{-7}*1.2*344} =1.14*10^{-2}Pa[/tex]
What is the main form of energy present in the initial state? (Initial state is when the rubber band is stretched , just before it is released)
O gravitational potential
O kinetic
O thermal
O elastic potential
The object has a mass of 100kg. The Tension is 200N[U]. What is the acceleration of this elevator? *
A) 8m/s/s
B) 8m/s/s[D]
C) 9.8m/s/s[D]
D) 0.5m/s/s[D]
Answer:
So the answer is B. A is wrong because negative answer = deceleration
Find the X and Y components of the following:
A. 35 m/s at 57q from the x-axis.
Explanation:
Given that,
35 m/s at 57° from the x-axis.
Speed, v = 35 m/s
Angle, θ = 57°
Horizontal component,
[tex]v_x=v\cos\theta\\\\=35\times \cos(57)\\\\=19.06 m/s[/tex]
Vertical component,
[tex]v_y=v\sin\theta\\\\v_y=35\times \sin(57)\\\\=29.35\ m/s[/tex]
Hence, this is the required solution.
Which electromagnetic waves have the greatest frequencies?
Answer:
Gamma rays
Explanation:
Gamma rays have the highest frequency in the electro magnetic spectrum
If a Charged particle at rest experiences no electromagnetic force. what happens?
Answer: Electromagnetic force is the force on charged particle due to both electric field and magnetic field. ... Magnetic force can be experienced by charges in motion. Hence, if a charged particle kept at rest experiences an electromagnetic force, the electric field must not be zero and the magnetic field may or may not be zero.
Explanation: Hope it help
Calculate the RMS voltage of the following waveforms with 10 V peak-to-peak:
a. Sine wave;
b. Square wave,
c. Triangle wave.
Calculate the period of a waveform with the frequency of:
a. 100 Hz,
b. 1 kHz,
c. 100 kHz.
Answer:
a) [tex]T=0.01s[/tex]
b) [tex]T=0.001s[/tex]
c) [tex]T=0.00001s[/tex]
Explanation:
From the question we are told that:
Given Frequencies
a. 100 Hz,
b. 1 kHz,
c. 100 kHz.
Generally the equation for Waveform Period is mathematically given by
[tex]T=\frac{1}{f}[/tex]
Therefore
a)
For
[tex]T=100 Hz[/tex]
[tex]T=\frac{1}{100}[/tex]
[tex]T=0.01s[/tex]
b)
For
[tex]F=1kHz[/tex]
[tex]T=\frac{1}{1000}[/tex]
[tex]T=0.001s[/tex]
c)
For
[tex]F=100kHz[/tex]
[tex]T=\frac{1}{100*100}[/tex]
[tex]T=0.00001s[/tex]
in physics If we interchange rows and columns of Matrix A, what is the new matrix known as 'Matrix' A ?
Answer:
The correct answer is (C), as explained below. The transpose of a matrix is created by interchanging corresponding rows and columns.
Switching Rows
You can switch the rows of a matrix to get a new matrix.
Explanation:
If A is an m × n matrix and AT is its transpose, then the result of matrix multiplication with these two matrices gives two square matrices: A AT is m × m and AT A is n × n. ... Indeed, the matrix product A AT has entries that are the inner product of a row of A with a column of AT.
When the distance between two charges I no halved, the electric force between the charges
A) quadruples
B) doubles
C) is half
D) is reduced by one quarter
Answer:
A)quadruples
Explanation:
The force between the two charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. Hence, if distance between charges is halved (charges remaining kept constant), the force between the two charges is quadrupled
In the figure below, this “double” nozzle discharges water (at 10°C, density= 1000 kg/m3) into the atmosphere at a rate of 0.50 m3/s. The pressure at the inlet is to be 315612 Pa. If the nozzle is lying in a horizontal plane. Jet A is 10 cm in diameter, jet B is 12 cm in diameter, and the pipe (1) is 30 cm in diameter. The x-component of force (Rx) acting through the flange bolts is required to hold the nozzle in place is:
Answer:
gfxfhhnhgfhjjgfghjhffgkhfdcg
who won the battle of Buxar
Answer:
British East India Company
The battle was fought at Buxar, a "small fortified town" within the territory of Bihar, located on the banks of the Ganga river about 130 kilometres (81 mi) west of Patna; it was a decisive victory for the British East India Company.
Suppose there are 3 molecules in a container. If each molecule has a 1-in-2 chance of being in the left half of the container, what is the probability that there are exactly 2 molecules in the left half of the container?
Answer:
Total probability = 3/8
Explanation:
Below is the calculation:
Number of molecules in the container = 3
The probability of one molecule in the left half, P = 3 / 2 = 1.5 or 1/2
The probability of second molecule in the left half, P1 = (3/4)
Total probability = P x P1
Total probability = (1/2) x (3/4)
Total probability = 3/8
What type of Earth scientist would be interested in understanding volcanic eruptions on
the seafloor?
Answer:
Marine geologists learn about the rocks and geologic processes of the ocean basins.
name of this musician and some of his songs
Answer:
Bobby Benson..........taxi driver
Dr Victor Olaiya......... omo pupa
prince Nic Mbarga.........sweet mother
sir Victor Uwaifor............. mammy water
Answer:
hey ...................................... what's up
What happens when sulfur reacts with lithium?
A. Electrons move from the lithium atoms to the sulfur atoms.
B. Electrons become delocalized among the atoms. C. Electrons are shared between the lithium atoms and the sulfur atoms.
D. Electrons move from the sulfur atoms to the lithium atoms.
Answer: A.
Lithium sulfide is the inorganic compound with the recipe Li2S. It solidifies in the antifluorite theme, depicted as the salt (Li+)2S2−. It frames a strong yellow-white deliquescent powder. In air, it effectively hydrolyses to deliver hydrogen sulfide (spoiled egg scent).
A horizontal force is applied to a 4.0 kg box. The box starts from rest, moves a horizontal distance of 10.0 meters, and obtains a velocity of 7.0 m/s. The change in the kinetic energy is:_____.
Answer:
98 J
Explanation:
Applying,
Change in kinetic energy = Final kinetic energy- initial kinetic energy
ΔK.E = mv²/2-mu²/2..............Equation 1
Where ΔK.E = Change in kinetic energy, m = mass of the box, u = initial velocity of the box, v = final velocity of the box.
From the question,
Given: m = 4.0 kg, u = 0 m/s, v = 7 ,0 m/s
Substitute these values into equation 1
ΔK.E = (4(7²)/2)-(4(0²)/2)
ΔK.E = (2×49)-0
ΔK.E = 98 J
Hence the change in kinetic energy 98 J
A block is projected with speed v across a horizontal surface and slides to a stop due to friction. The same block is then projected with the same speed v up an incline where is slides to a stop due to friction. In which case did the total mechanical energy of the block decrease the least
Answer: C. The case on the inclined surface had the least decrease intotal mechanical energy.
Explanation:
First and foremost, it should be noted that the mechanical energy is the addition of the potential and the kinetic energy.
From the information given, it should be known that when the block is projected with the same speed v up an incline where is slides to a stop due to friction, the box will lose its kinetic energy but there'll be na increase in the potential energy as a result of the veritcal height. This then brings about an increase in the mechanical energy.
Therefore, the total mechanical energy of the block will decrease the least when the case on the inclined surface had the least decrease intotal mechanical energy.
An empty parallel plate capacitor is connected between the terminals of a 8.85-V battery and charges up. The capacitor is then disconnected from the battery, and the spacing between the capacitor plates is doubled. As a result of this change, what is the new voltage between the plates of the capacitor
Answer:
The new voltage is 17.7 V.
Explanation:
Voltage, V = 8.85 V
The spacing is doubled.
When it is disconnected, the charge remains same,
q = C V ..... (1)
where, C is the capacitance, V is the voltage.
The capacitance is inversely proportional to the distance between the two plates.
So, when the spacing is doubled, the capacitance is halved.
Let the new voltage is V'.
C V = C' V'
C x 8.85 = C/2 x V'
V' = 17.7 V
In an experiment, a shearwater (a seabird) was taken from its nest, flown a distance 5120 km away, and released. It found its way back to its nest 12.5 days after release. If we place the origin at the nest and extend the + x-axis to the release point, what was the bird’s average velocity in m/s:
a. for the return flight
b. for the whole episode, from leaving the nest to returning
Answer:
a) v = -4.74 m / s, b) v = 0 m / s
Explanation:
Average speed is
v = Δx /Δt
a) the variation of the distance on the return trip is
Δx = -5120 km = -5120 10³ km
the negative sign is because the bird is going back
Δt = 12.5 days (24 h / 1 day) (3600 s / 1 h) = 1.08 10⁶ s
v = -5120 10³ / 1.08 10⁶
v = -4.74 m / s
b) the displacement for the round trip is zero, therefore the average velocity is
v = 0 m / s
Explain how the Laws of planetary motion and Newton’s laws allow the hotel to keep moving in space.
Answer:
Explanation:
i am sorry i needed points
A 1 pF capacitor is connected in parallel with a 2 pF capacitor, the parallel combination
then being connected in series with a 3 pF capacitor. The resulting combination is then
connected across a battery.
(a) Which capacitor has the greatest charge?
(b) Which capacitor has the greatest voltage?
Answer:
a)3pF has the greatest charge
b) 3pF to have the greatest voltage.
Explanation:
From the question we are told that:
1pF is parallel to [tex]2pF =1pF//2pF[/tex]
And 3pF is in with series 1pF is parallel to[tex]2pF =3pF+(1pF//2pF)[/tex]
Generally the equation for Resultant capacitor is mathematically given by
[tex]C=3pF+(1pF//2pF)[/tex]
[tex]C=\frac{3}{2}pF[/tex]
Ohm's law
Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points
a)
Since
The same charge flowing through [tex]1pF//2pF[/tex] flow through 3pF
Therefore
3pF has the greatest charge
b)
Voltage drop in series according to ohms law
Therefore the parallel share same voltage
Given
3pF to have the greatest voltage.
how many atoms are in a 4.7 g copper coin?
Answer:
x = 4.45 * 10 ^22 Note. Technically, this should be rounded to 4.5 * 10^22. There are only 2 sig digits.
Explanation:
You have to assume that the coin is pure copper, which I doubt. What a coin is actually made of depends on when it was minted. But for the sake of this question, we'll assume coins are pure copper.
Copper has an atomic mass of 63.546 grams / mol
So 4.7 g of copper = 4.7 / 63.545 mol
We have 0.07396 mol of copper
1 mol of anything = 6.02 * 10^23 atoms (in this case).
0.07396 mol = x
Cross Multiply
1 * x = 0.07396 * 6.02 * 10^23
x = 4.45 * 10 ^22 atoms of copper