Answer:
the correct answer is B
Explanation:
Let's propose the solution of the problem, for this we form a system formed by the two cars, so that the forces during the collision are internal, the momentum is conserved
instantly starts. Before the crash
p₀ = M v +0
final instant. After the crash
m_f = (M + M) v_f
the moment is preserved
p₀ = p_f
M v = 2 M v_f
v_f = v / 2
let's look for kinetic energy
before the crash
K₀ = ½ M v²
after the crash
K_f = ½ 2M (v_f)²
K_f = ½ 2M (v/2)²
K_f = (½ M v²) ½
K_f = K₀ / 2
therefore the correct answer is B
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
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.
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
Which electromagnetic waves have the greatest frequencies?
Answer:
Gamma rays
Explanation:
Gamma rays have the highest frequency in the electro magnetic spectrum
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
A toy car rolls down a slope. If it takes 5.94 s to accelerate from 3.22 m/s to 12.4 m/s, what is the value of the acceleration?
2.01 m/s2
1.35 m/s2
1.55 m/s2
0.219 m/s2
Answer:
a = 1.55m/s²
Explanation:
a = (v_f-v_0)/t
a = (12.4m/s-3.22m/s)/5.94s
a = 1.55m/s²
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 ball with a mass of 275 g is dropped from rest, hits the floor, and rebounds upward. If the ball hits the floor with a speed of 2.60 m/s, rebounds with a speed of 1.84 m/s, and is in contact with the floor for 1.40 ms,determine the following.
(a) magnitude of the change in the ball's momentum (Let up be in the positive j hat direction.)
_______________kg
Answer:
-0.209 kg.m/s
Explanation:
The mass of the ball, m = 275g or 0.275 kg
Speed or velocity, v = 2.60 m/s
Momentum, P = mv
Momentum when velocity is 2.60 = 0.275 x 2.60 = 0.715 kg.m/s
Speed or velocity, v = 1.84 m/s
Momentum, P = mv
Momentum when velocity is 1.84= 0.275 x 1.84 = 0.506 kg.m/s
Change in magnitude = 0.506 - 0.715 = -0.209 kg.m/s
Diwn unscramble the word
Answer:
WIND Is what you're looking for
Explanation:
The word is WIND
2. A Plate 0.02 mm distance from a fixed Plate moves at a velocity Of 0.6mls and requires a force of 1.962 N Per unit area to maitain this Speed. Determine the viscosity of the fluid between the plates?
Answer:
6.54 × 10⁻⁵ Pa-s
Explanation:
Since the shear force, F = μAu/y where μ = viscosity of fluid between plates, A = area of plates, u = velocity of fluid = 0.6 m/s and y = separation of plates = 0.02 mm = 2 × 10⁻⁵ m
Since F = μAu/y
F/A = μu/y where F/A = force per unit area
Since we are given force per unit area, F/A = 1.962 N per unit area = 1.962 N/m²
So, μ = F/A ÷ u/y
substituting the values of the variables into the equation, we have
μ = F/A ÷ u/y
μ = 1.962 N/m² ÷ 0.6 m/s/2 × 10⁻⁵ m
μ = 1.962 N/m² ÷ 0.3 × 10⁵ /s
μ = 6.54 × 10⁻⁵ Ns/m²
μ = 6.54 × 10⁻⁵ Pa-s
Two identical ambulances with loud sirens are driving directly towards you at a speed of 40 mph. One ambulance is 2 blocks away and the other is 10 blocks away. Which of the following is true? [Note that pitch = frequency.]a) The siren from the closer ambulance sounds higher pitched to you.b) The siren from the farther ambulance sounds higher pitched to you.c) The pitch of the two sirens sounds the same to you.d) The siren from the farther ambulance sounds higher pitched, until the closer ambulance passes you.
Answer:
c) The pitch of the two sirens sounds the same to you
Explanation:
The pitch does not depend on the distance of the object from the observer.
As per the given data
pitch = frequency
Frequency = [tex]f_{0}[/tex] [tex]\frac{V +- V_{0}}{V +- V_{s}}[/tex]
[tex]f^{'}[/tex] = [tex]f_{0}[/tex] [tex]\frac{V }{V - V_{s}}[/tex]
Hence, the pitch of the two sirens remains the same for the observer.
Answer:
c) The pitch of the two sirens sounds the same to you
Explanation:
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.
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
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 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).
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.
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
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
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
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.
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]
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
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.
calculate the electrical potential at a point P a distance of 1 m from either two to charge of +10 micro coulomb and -5 micro coulomb which are 10 cm apart calculate also the potential energy of a +2 micro coulomb charge placed at a point p
Answer:
a) V = 45 10³ V, b) U = 4.59 J
Explanation:
a) The electric potential for a series of point charges is
V = k ∑ [tex]\frac{q_i}{r_i}[/tex]
in this case point P is at a distance of 1 m from each charge, so the point is located perpendicular to the charges at its midpoint
V = k ( [tex]\frac{q_1}{r} + \frac{q_2}{r}[/tex])
V = 9 10⁹ (10 - 5/ 1) 10⁻⁶
V = 45 10³ V
b) the potential energy is
U = k ( [tex]\frac{q_1q}{r} + \frac{q_2q}{r} + \frac{q_1q_2}{r_2}[/tex] )
where r = 1m and r₂ is the distance between the two charges r₂ = 0.10 m
U = 9 10⁹ (10 2 / 1 - 5 2/1 - 10 5 /0.10) 10⁻¹²
U = 9 10⁻³ 510
U = 4.59 J
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:
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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
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
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
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.