Answer:it B
Explanation:I took the test
Mention two ways in which the effects of friction can be minimised
Answer:
Polishing the rough surface.
Oiling or lubricating with graphite or grease the moving parts of a machine.
Providing all bearings or wheels between the moving parts of a machine or vehicles reduce friction and allow smooth movement as rolling friction is less than sliding friction.
Explanation:
Can I please have help
Answer:
it will usually increase
Explanation:
potato
A child makes a ramp to push his toy dump truck up to his sandbox. If he uses 5 newtons of force to push the 12-newton truck up the ramp, what is the mechanical advantage of his ramp?
Answer:
m = 2.4
Explanation:
Given that,
Input force, [tex]F_i=5\ N[/tex]
Output force, [tex]F_o=12\ N[/tex]
We need to find the mechanical advantage of the ramp. The ratio of output force to the input force is equal to mechanical advantage. So,
[tex]m=\dfrac{12}{5}\\\\m=2.4[/tex]
So, the mechanical advantage of his ramp is 2.4.
Which of the following is an example of predation?
Answer:
an owl hunts, catches, and consumes a field mouse for energy
Explanation:
D
If you increase the
frequency of a
wave, what
happens to the
speed?
G
A. It decreases.
B. It stays the same.
C. It increases.
D. It can increase or decrease.
Answer:
D
Explanation:
I think you got it right
Riders in an amusement park ride shaped like a Viking ship hung from a large pivot are rotated back and forth like a rigid pendulum. At each end of the swing the ship hangs motionless for a moment before the ship swings down under the influence of gravity. Assume that this motionless point occurs when the bar connecting the pivot point and the ship is horizontal.
Required:
a. Assuming negligible friction, find the speed of the riders at the bottom of its arc, given the system's center of mass travels in an arc having a radius of 14.0 m and the riders are near the center of mass.
b. What is the centripetal acceleration at the bottom of the arc?
c. Draw a free body diagram of the forces acting on a rider at the bottom of the arc.
d. Find the force exerted by the ride on a 60.0 kg rider and compare it to her weight.
e. Discuss whether the answer seems reasonable.
Answer:
a) v = 16.57 m / s, b) a = 19.6 m / s², d) N = 1.76 10³ N, N / W = 3
Explanation:
This exercise looks interesting, but I think you have some problem with the writing, the questions seem a bit disconnected from the initial text.
Let's answer the questions.
a) For this part we can use energy considerations.
Starting point. The upper part of the trajectory indicates that the arm is horizontally
Em₀ = U = m g h
in this case h = r
Final point. For lower of the trajectory
Em_f = K = ½ m v²
as they indicate that there is no friction
Em₀ = em_f
mgh = ½ m v²
v = [tex]\sqrt{2gh}[/tex]
let's calculate
v = [tex]\sqrt{2 \ 9.8 \ 14.0}[/tex]
v = 16.57 m / s
b) the centripetal acceleration has the formula
a = v² / r
a = 16.57² / 14.0
a = 19.6 m / s²
c) see attached where the diagram is
where N is the normal and w the weight
d) let's use Newton's second law
N-W = m a
N - mg = m ar
N = m (g + a)
let's calculate
N = 60.0 (9.8 + 19.6)
N = 1.76 10³ N
the relationship with weight is
N / W = 1.76 10³/( 60 9.8)
N / W = 3
normal is three times greater than body weight
e) the answer is reasonable since by Newton's first law the body must continue in a straight line, therefore to change its trajectory a force must be applied to deflect it
Please help. It’s probably easy
The plates of a vacuum-gap parallel plate capacitor have a 100.0 mm2 area, a vacuum gap of 5.00 mm and are connected to a 1.5-volt battery. After the capacitor is charged, the battery is disconnected from the capacitor. After the battery is disconnected, the plates are pulled apart until the vacuum gap is 7.50 mm. a. What are the initial and final energies stored in the capacitor
Answer:
E₀ = 2.0*10⁻¹¹ J = 0.2 pJ
Ef = 3.0*10⁻¹¹ J = 0.3 pJ
Explanation:
The energy stored between the plates of a parallel plate capacitor can be expressed in terms of the capacitance C and the potential difference between plates V as follows:[tex]E = \frac{1}{2} * C * V^{2} (1)[/tex]
When the capacitor is fully charged, the potential difference between plates must be equal to the voltage of the battery, 1.5 V.In a parallel plate capacitor, the value of the capacitance is independent of the applied voltage, and depends only on geometric constants and the dielectric constant of the medium between plates, as follows:[tex]C = \frac{\epsilon_{o}*A}{d} (2)[/tex]
We can find the initial value of C replacing in (2) by the givens below:A = 100.0 mm2d= 5.00 mmε₀ = 8.85*10⁻¹² F/m[tex]C_{o} = \frac{\epsilon_{o}*A}{d} = \frac{(8.85*(10)^{-12} F/m)*(10^{-4} m2)}{5.0*(10)^{-3}m} = 1.77*10^{-13} F (3)[/tex]With this value of C₀, and the value of the initial potential difference between plates (1.5 V), we can find the initial charge on the capacitor, starting from the definition of capacitance:[tex]C =\frac{Q}{V} (4)[/tex]Solving for Q in (4):[tex]Q = C_{o}* V = 1.77*10^{-13} F * 1.5 V = 2.65*10^{-13} C (5)[/tex]Finally, we can find the initial energy stored in the capacitor, replacing (3) and V in (1):[tex]E_{o} = \frac{1}{2} * C_{o} * V_{o} ^{2} = \frac{1}{2} * 1.77*10^{-13}F*(1.5V)^{2} = 0.2 pJ (6)[/tex]
If we pull apart the plates until the vacuum gap is 7.50 mm, we will change the expression of C in (2), decreasing its value due to the expanded gap.Replacing in (2) the new value of the gap (7.50 mm), we can find the new value of C, as follows:[tex]C = \frac{\epsilon_{o}*A}{d} = \frac{(8.85*10^{-12}F/m)*10^{-4} m2}{7.5*10^{-3}m} = 1.18*10^{-13} F (7)[/tex] In order to find the final energy stored in the capacitor, we need also the value of the final potential difference between plates.Once disconnected from the battery, the charge on any of the plates must remain the same, due to the principle of conservation of the charge.So, since we have the value of Q from (5) and the new value of C from (7), we can find the new potential difference between plates as follows:[tex]V_{f} = \frac{Q}{C_{f}} = \frac{2.7*10^{-13}C}{1.18*10^{-13}F} = 2.25 V (8)[/tex]With the values of Vf and Cf, we can find the value of the final energy stored in the capacitor, replacing these values in (1):[tex]E_{f} = \frac{1}{2} * C_{f} * V_{f} ^{2} = \frac{1}{2} * 1.18*10^{-13}F*(2.25V)^{2} = 0.3 pJ (9)[/tex]
How can parents help children to gain friends?
Answer:
You could try finding a familiar peer to join the activity with your child. Or ask your child who their friends are at school, or what they look for in a friend at school.
Answer:
Let the parents their Children to play outside
Explanation:
I HOPE I HELP YOU
Please help !!!!!!!!!!!!
Answer:
152 Volts
Explanation:
First, the Resistors are in series. So, the net resistance, R = 3 + 4 +3 + 4 +5
= 19 ohms
Using, V = IR;
V (the needed P.D) = 8 x 19 = 152 Volts
will be needed to successfully transport 8 amps of current round the circuit
Answer:
4q
Explanation:
wait nvm i dont know
a solid disk rotates in the horizontal plane at an angular velocity of 4.9 x 10 rad/s with respect to an axis perpendicular to the disk at its center the moment of inertia of the disk is 0.14 kg from above sand is dropped straight down onto this rotating disk so that a thin unifrom ring of sand is formed at distance of 0.4 m from the axis the sand in the ring has mass of 0.5 kg after all the sand is in place what is the angular velocity of the disk
Answer:
ωf = 3.1*10 rad/sec
Explanation:
Assuming no external torques acting while the sand is being dropped, total angular momentum must keep constant.So we can write the following equality:[tex]L_{o} = L_{f} (1)[/tex]
For a rigid body rotating with respect to an axis, the angular momentum can be written as follows:[tex]L = I* \omega (2)[/tex]
where I = moment of inertiaω = angular velocityReplacing (2) on both sides of (1) we get:[tex]I_{o}* \omega_{o} = I_{f}* \omega_{f} (3)[/tex]
In (3) we know the values of I₀ and ω₀ (since they are givens), but we need to find the value of If first.The final moment of inertia, will be equal to the sum of the initial one, plus the one due to the ring of sand, that also rotates with respect to an axis perpendicular to the disk, as follows:[tex]I_{f} = I_{o} + I_ {ring} (4)[/tex]The moment of inertia of a circular ring is as follows:[tex]I_{ring} = m_{ring} *r^{2} (5)[/tex]
Replacing by the givens in (5) we get:[tex]I_{ring} = m_{ring} *r^{2} = 0.5 kg * (0.4m)^{2} = 0.08 kg*m2 (6)[/tex]
Replacing (6) in (4):[tex]I_{f} = I_{o} + I_ {ring} = 0.14kg*m2 + 0.08 kg*m2 = 0.22 kg*m2 (7)[/tex]Replacing I₀, ω₀ and If in (3), we can solve for ωf, as follows:[tex]\omega_{f} =\frac{I_{o} *\omega_{o} }{I_{f} } = \frac{0.14kg*m2*4.9*10rad/sec}{0.22kg*m2} = 3.1*10 rad/sec (8)[/tex]What is a energy transformation when using a microwave to make popcorn?
Answer:
Radiation
Explanation:
Radiant energy
Explanation:
Radiant energy is transformed into thermal energy as the popcorn kernels absorb the microwaves. This causes the kernels to become hot and pop. Electric energy is transferred from the electrical outlet to the microwave.
What speed must a 600 kg car have in order to have the same momentum as a 1200 kg truck traveling at a velocity of 10 m/s to the west? 5 m/s west B 20 mls west 5 m/s east 20 m/s east
A) 5m/s west
B) 20m/s west
C) 5m/s east
D) 20m/s east
Answer:
20 m/s
Explanation:
Two identical positive charges exert a repulsive force of 6.4x10^-9 N when separated by a distance of 3.8x10^10 m. Calculate the charge of each.
Answer:F = kq2/d2 ⇒
q = √(Fd2/k)
q = d √(F/k)
d = 3.8 x 10-10 m
F = 6.4 x 10-9 N
Look up k in your physics book in appropriate units, and plug in the numbers. You should get q in coulombs.
Explanation:
The value of each charge will be 1.64 ×10⁻⁴. The concept of the columb force is used.
What is the charge?When the matter is put in an electromagnetic field, it has an electric charge, which causes it to experience a force. A positive or negative electric charge can exist.
Charges that are similar repel each other, whereas charges that are dissimilar attract each other. The term "neutral" refers to an item that has no net charge.
[tex]\rm F =K \frac{q_1Q_2}{d^2} \\\\ F = K\frac{q^2}{d^2} \\\\ q = \sqrt{\frac{dF}{k} } \\\\ q = \sqrt{\frac{3.8 \times 10^{10}\times 6.4 \times 10^{-9}}{9 \times 10^9} } \\\\ q=1.64 \times 10-4[/tex]
Hence the value of each charge will be 1.64 ×10⁻⁴. The concept of the columb force is used.
To learn more about the charge refer to the link;
https://brainly.com/question/24391667
A vibrating mass of 300 kg mounted on a massless support by a spring of stiffness 40,000 N>m and a damper of unknown damping coefficient is observed to vibrate with a 10-mm amplitude while the support vibration has a maximum amplitude of only 2.5 mm (at resonance). Calculate the damping constant and the amplitude of the force on the base.
Answer:
400 N
Explanation:
[tex]\text { Given: } m=300 \mathrm{~kg}, k=40,000 \mathrm{~N} / \mathrm{m}, \omega_{b}=\omega_{n}(r=1), X=10 \mathrm{~mm}, Y=2.5 \mathrm{~mm}[/tex] .
Find damping constant
[tex] \frac{X}{Y}=\left[\frac{1+(2 \zeta r)^{2}}{\left[\left(1-r^{2}\right)^{2}+(2 \zeta r)^{2}\right.}\right]^{1 / 2} \\ \left.\frac{10}{2.5}=\frac{\left\lceil 1+4\zeta^{2}\right]^{1 / 2}}{4 \zeta^{2}}\right] \\ 16=\frac{1+4 \zeta^{-2}}{4 \zeta^{2}} \\ \zeta^{2}=\frac{1}{60}=\frac{c^{2}}{4 k m} \\ c=\sqrt{\frac{4(40,000)(300)}{60}} \\ c=894.4 \mathrm{~kg} / \mathrm{s}[/tex]
Amplitude of force on base:
[tex]F_{T}=k Y r^{2}\left[\frac{1+(2 \zeta r)^{2}}{\left(1-r^{2}\right)^{2}+(2 \zeta r)^{2}}\right]^{1 / 2}[/tex]
substituting the values in above formula we get
F_T = 400 N
It's your birthday, and to celebrate you're going to make your first bungee jump. You stand on a bridge 100m above a raging river and attach a 35-m-long bungee cord to your harness. A bungee cord, for practical purposes, is just a long spring, and this cord has a spring constant of 43N/m . Assume that your mass is 79kg . After a long hesitation, you dive off the bridge. How far are you above the water when the cord reaches its maximum elongation? h=
Answer:
h = 47 m
Explanation:
First, we will calculate the force on the cord due to the weight:
[tex]Force = F = Weight\\F = mg\\F = (79\ kg)(9.81\ m/s^2)\\F = 775\ N[/tex]
Now, we will calculate the elongation by using Hooke's Law:
[tex]F = k \Delta x[/tex]
where,
k = spring constant = 43 N/m
Δx = elongation = ?
Therefore,
[tex]775\ N = (43\ N/m)\Delta x\\\\\Delta x = \frac{775\ N}{43\ N/m}\\\\\Delta x = 18\ m\\[/tex]
So, the final length of the cord will be:
[tex]Final\ Length = Initial\ Length + \Delta x\\Final\ Length = 35\ m + 18\ m\\Final\ Length = 53\ m\\[/tex]
Hence, the height from water (h) can be found using the following formula:
[tex]h = Height\ of\ Bridge - Final\ Length\ of\ cord\\h = 100\ m - 53\ m\\[/tex]
h = 47 m
The body mass of Asaiah is 70 Kg.
(a) What is his weight on Earth?
(b) If he goes to the Moon,
(i) What is his mass?
(ii) What is his weight?
Answer:
A I hope its not wrong I hope u do good
a man pushed on the side ..
Answer:
B.will increase the maximum static friction between the box and the floor
Explanation:
Because static friction is the force that keeps an object at rest
Compare and contrast the solar eclipse seen in this video to a lunar eclipse.
Answer: sadly, I can’t see the video. However, a lunar eclipse happens when the moon is hidden by the earth’s shadow. A solar eclipse occurs when the moon casts a shadow on the earth.
Explanation: I’m not completely sure if this is what you were looking for, but I hope it helps anyway.
Please help me !!!!!!!
Answer: I believe that it is 35 Joules.
Explanation:
100 - 65 = 35
:)
There are two main types of collisions that you will study: elastic and perfectly inelastic. In an elastic collision, kinetic energy is conserved. In a perfectly inelastic collision, the particles stick together and thus retain the same velocity after the collision.
a. True
b. False
Answer:
The first part is right (KE is conserved in an elastic collision).
The second part of the statement is false,.
Since momentum is conserved, let moving mass m strike stationary mass M:
m v = (m + M) V where m v is the momentum in
Obviously, v does not equal V.
Unless otherwise stated, all objects are located near the Earth's surface, where g = 9.80 m/s2 .
A force acts on a 1.5 kg , mass, giving it an acceleration of 3.0 m/s2 .
1. If the same force acts on a 3.0 kg mass, what acceleration would be produced?
2. What is the magnitude of the force?
Answer:
1) 1.5 m/s^2
2) 4.5 N
Explanation:
From Newton's Second Law of motion, we know
[tex]F=m*a[/tex]
Which states that to calculate the force acting on an object, you multiply its mass and acceleration.
So, we know an object of mass 1.5 kg has an acceleration of 3 m/s^2, then
[tex]F=m*a=1.5*3=4.5[/tex]
A force of 4.5 N is acting on the object.
If a force of 4.5 N acts on a mass of 3kg we have
[tex]a=\frac{F}{m}=\frac{4.5}{3}=1.5[/tex]
So, it would give it an acceleration of 1.5 m/s^2.
The total charge a battery can supply is rated in mA⋅hmA⋅h, the product of the current (in mA) and the time (in h) that the battery can provide this current. A battery rated at 1000mA⋅h can supply a current of 1000 mA for 1.0 h, 500 mA current for 2.0 h, and so on. A typical AA rechargeable battery has a voltage of 1.2 V and a rating of 1800mA⋅h. For how long could this battery drive current through a long, thin wire of resistance22Ω?
Answer:
118800 seconds
Explanation:
Given :
Voltage, V = 1.2 V
Resistance, R = 22 Ω
Applying Ohm's law, we get
Voltage, V = IR
Current [tex]$I=\frac{V}{R}$[/tex]
[tex]$I=\frac{1.2}{22}$[/tex]
I = 0.0545 A
Rate = 1800 mAh
Time taken, [tex]$t=\frac{1800 \times 10^{-3}}{0.0545}$[/tex]
= 33 hr
= 118800 s
Which of the following represents a concave lens?
A. -di
B. +di
C. -f
D. +f
Answer:
The answer is option D. +f
Option D represents a concave lens. There are two types of lenses, one is a concave lens while the other is the convex lens.
What is the definition of a concave lens?A concave lens deviates a direct beam from the source into a reduced form. At minimum, one interior face of concave lenses is curved.
Because it is curved round inwards at the center and bulges outwards through the edges, causing the light to diverge, a concave lens is also known as a diverging lens.
It forms an upright , virtual picture both real and virtual pictures are formed from the concave lens.
The image formed from the positive side of the focus of the lens.+f shows the positive side of the focus of the lens.f is the focal length.
Hence, option D represents a concave lens
To learn more about the concave lens, refer to the link;
https://brainly.com/question/2919483
#SPJ2
how is a trench and a tsunami related? 6-8 sentences
Answer: A tsunami is a very long-wavelength wave of water that is generated by sudden displacement of the seafloor or disruption of any body of standing water. Tsunami are sometimes called "seismic sea waves", although they can be generated by mechanisms other than earthquakes. Tsunami have also been called "tidal waves", but this term should not be used because they are not in any way related to the tides of the Earth. Because tsunami occur suddenly, often without warning, they are extremely dangerous to coastal communities. Ocean trenches are steep depressions in the deepest parts of the ocean [where old ocean crust from one tectonic plate is pushed beneath another plate, raising mountains, causing earthquakes, and forming volcanoes on the seafloor and on land.
Explanation:
Which planet is least like earth? Mars,Venus, or Jupiter
Answer:
mars, reason why is because they both are diff from the size
Explanation:
The modern model of the atom describes electrons in a little less specific detail than earlier models did. Why is it that being less sure about the placement of electrons in an atom is actually an improvement over earlier models?
The plum pudding model of the atom states that
Answer:
It is because one cannot know exactly the position of the electron within the atom.
One formulation of Heisenberg's Uncertainty Principle tells us that one cannot know simultaneously the position and momentum of the electron, so one cannot specify exactly either coordinate because the other would be infinite.
Bohr specified the most probable position of the electron at its lowest energy level in hydrogen and the product of the two would be about the Heisenberg value.
a potted plant falls from a window sill and is gaining speed. which one of the following statements is true of the plant?
a) its kinetic energy is constant
b) its kinetic energy is increasing
c) its kinetic energy is decreasing
I need help plissss..............
Cartesian coordinate system is used for?
Answer:
sorry not sure but i can try help with telling you this...
Explanation:
alls you havs to do is ask the internet and it will tell you