A sphere has a mass of 8.5 kg and a radius of 10cm. How much work is it necessary to do on the ball to get it to a speed of 6.0m/s?
Answer:
153JExplanation:
Step one:
given data
mass m= 8.5kg
radius r= 10cm in meters = 0.01m
velocity v= 6m/s
The work done will be the same as the energy possessed by the sphere at such speed
Required
the work one in Joules
we know that
KE=1/2mv^2
KE=1/2*8.5*6^2
KE= 1/2*8.5*36
KE=306/2
KE=153J
A train slows from 44 m/s to 19 m/s in 9 seconds. What is the train's acceleration? Show your work.
Answer:
a = 2.77 [m/s²]
Explanation:
To solve this problem we must use the following equation of kinematics.
[tex]v_{f} =v_{o} -a*t[/tex]
where:
Vf = final velocity = 19 [m/s]
Vo = initial velocity = 44 [m/s]
a = acceleration [m/s²]
t = time = 9 [s]
Note: The negative sign in the above equation means that the train is decreasing its velocity.
19 = 44 - a*9
9*a = 44 -19
a = 2.77 [m/s²]
Check how you understand the principles of working of lenses. In some optical setup consisting of a single lens and an object magnification factor is measured as m-+4. We can conclude that:__________ a. Lens is converging, image is at the opposite side of lens from the object b. Lens is converging, image is the same side of lens as object c. Lens is diverging, image is at the opposite side of lens from the object d. Lens is diverging, image is the same side of lens as object
Answer:
b. Lens is converging, image is the same side of lens as object
Explanation:
A single converging lens is often used as a magnifying glass. The reason, behind its use as a magnifying glass is the configuration of the converging lens, when an object is placed inside its focal length. It forms the image of that object as magnified and at the same side as the object. So, the image is both magnified and erect. In this way, the converging lens serves as a magnifying glass with certain magnification factor, single handedly. The ray diagram of a magnifying glass is attached for reference. So, the correct option is:
b. Lens is converging, image is the same side of lens as object
The mass of an empty flask is 49.74 g. Filled with 120 cm 3 of acetone, the mass of the flask is found to be 144.78 g. What is the density of acetone?
Answer:
0.79g/cm³
Explanation:
Given parameters:
Volume of acetone = 120cm³
Mass of empty flask = 49.74g
Mass of flask + acetone = 144.78g
Unknown:
Density of acetone = ?
Solution:
Density is the mass per given volume of a substance. It is mathematically expressed as;
Density = [tex]\frac{mass}{volume}[/tex]
Mass of acetone =( mass of flask + acetone) - mass of empty flask
Mass of acetone = 144.78 - 49.74 = 95.04g
Now insert the parameters and solve;
Density = [tex]\frac{95.04}{120}[/tex] = 0.79g/cm³
A group of big city tenants were upset about rising rent for their apartments, and decided to play a prank on the Building Manager. They went up to the top floor of the
building, which was 176.4 m above the sidewalk, and waited. They wanted to drop the balloon at just the right time, so they needed to make a quick calculation. How many
seconds before the Building Manager walks to the spot should they drop the balloon?
Answer:
t = 6 s
Explanation:
This is a free fall exercise
y = y₀ + v₀ t - ½ g t²
If the balloon is released its initial velocity is zero, when it reaches the floor its height is also zero, we substitute
0 = y₀ + 0 - ½ g t2
t = √(2yo / g)
let's calculate
t = √ (2 176.4 / 9.8)
t = 6 s
the balloon must be released 6 s before the person reaches the building
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Comentarios
An airplane takes off northwest from Dallas to Amarillo. This is an example of-
a. Speed
b. Velocity
c. Acceleration
Answer:
the answers is C. acceleration
Can power be negative in physics? I am doing a lab in which I run down the stairs as quickly as possible. They are 5.4m tall and my work is 5321.7 J. After calculating work, I got -5321.7 J. I am supposed to calculate my power used over 3 trials. The time for trial 1 was 4.69 and the seconds for trials 2 and 3 are 4.25. After calculating my power I got -1134.69 W and -1252.16 W. I am not sure if I got my power right. Is my power really negative or is my power positive?
Answer:
Yes.
Explanation:
A negative power would just represent a loss of power. So in your case it lost -1252.16 W
What would the distance be if a bicyclist traveled 4.5 hours at a speed of 20.0km/h?
8.
'A 6.00 kg ball, A, moving at velocity 3.00 m/s due east collides with a 6.00 kg ball, B, at rest.
After the collision, A moves off at 40.0°N of E and ball B moves off at 50.0° S of E
please help me.
Answer:
brrrrrakabrrrrrrrrra
Explanation:
Whoever answers correctly gets brainlist!
Infared = used by police
gamma = short wavelength
radio = largest wavelength
visible = only ones we can see
Answer: police use infred waves,
radio waves have largest wave length, the
only part of the spectrum seen by humans is visible waves
gamma waves have shortest wave length
Explanation:
Nicki rides her bike at a constant speed for 6 km. That part of her ride takes her 1 h. She then rides her bike at a constant speed for another 9
km. That part of her trip takes her 2 h. What is her average speed?
Answer:
24km/h
Explanation:
go it right on ingenuity 2020
True or false? An electric current is a continuous flow of electric charges through a material.
A computational model predicts the maximum potential energy a roller coaster car can have given its mass and its speed at the lowest point of its journey. Its mass is 350 kg, and it speed at a height of 0 m is 25 m/s. What is the prediction for its maximum potential energy?
109,375 J
765,625 J
218,750 J
87,750 J
Answer:
The prediction for its maximum potential energy is 109,375 J
Explanation:
Given;
mass of the coaster car, m = 350 kg
speed of the coaster car at the lowest point, v = 25 m/s
The coaster car will have maximum kinetic energy at the lowest point and based on law of conservation of mechanical energy, the maximum kinetic energy of the coaster car at the lowest point will be equal to maximum potential energy at the highest point.
[tex]K.E_{max} = P.E_{max}[/tex]
[tex]K.E_{max} = \frac{1}{2} mv^2\\\\K.E_{max} = \frac{1}{2} (350)(25)^2\\\\K.E_{max} =109,375 \ J[/tex]
[tex]Thus, P.E_{max} = 109,375 \ J[/tex]
Therefore, the prediction for its maximum potential energy is 109,375 J
what
material gives the soil its high fertility?
Answer:
Humus
Explanation:
Its Humus I believe. I remember learning something like this.
A projectile is fired horizontally off the top of a cliff with an initial velocity of 30 m/s. It hits the ground 2.0 seconds later. What is the height of the cliff?
Answer:no
Explanation:
What happens in a convection current?
Answer:
Convection currents are the result of differential heating. Lighter (less dense), warm material rises while heavier (more dense) cool material sinks. It is this movement that creates circulation patterns known as convection currents in the atmosphere, in water, and in the mantle of Earth.
Explanation:
The Doppler effect is the change in sound _____ caused by the motion of the sound source, motion of the listener, or both.
pitch
frequency
amplitude
speed
what is the mass of an object with a density of 74 g/mL and a volume of 7 mL?
Answer:
518 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volume
From the question we have
mass = 74 × 7
We have the final answer as
518 gHope this helps you
an object with a mass of 7.5 kg accelerates 8.3 m/s2 when an unknown force is applied to it. what is the amount of the force?
Answer:
I believe the answer is 62.25 N
Explanation:
You just multiply 7.5 and 8.3 and you get 62.25
Answer:
62.25N or 62.25 newtons
Explanation:
F=ma where F is the force in newtons, m is the mass in kilograms (kg), and a is the acceleration
m=7.5kg
a=8.3m/s^2
Therefore, F=ma=7.5*8.3=62.25N
The amount of force is 62.25N or 62.25 newtons
A torque of 0.97 N m is applied to a bicycle wheel of radius 35 cm and mass 0.75 kg. Assuming the wheel can be modelled as a hoop, find the angular acceleration of the wheel.
Answer:
11 rad/s^2 approx.Explanation:
Given
torque,τ= 0.97N
radius r= 35cm to m= 0.35m
mass m= 0.75kg
Required
angular acceleration
First, we need the moment of inertial of the wheel
I=mr^2
I=0.75*0.35^2
I=0.75*0.1225
I=0.09kgm^2
Secondly, the angular moment of inertial is expressed as
a=τ/I
a=0.97/0.09
a=10.77rads/s^2
a=11 rad/s^2 approx.
A nail driven into a board increases in temperature.
If 59.0 % of the kinetic energy delivered by a 1.60 kg hammer with a speed of 7.70 m/s is transformed into heat that flows into the nail and does not flow out, what is the increase in temperature of an 7.60 g aluminum nail after it is struck 10 times?
Answer:
ΔT = 40.91 °C
Explanation:
First we find the kinetic energy of one hit to the nail:
K.E = (1/2)mv²
where,
K.E = Kinetic energy = ?
m = mass of hammer = 1.6 kg
v = speed of hammer = 7.7 m/s
Therefore,
K.E = (1/2)(1.6 kg)(7.7 m/s)²
K.E = 47.432 J
Now, for 10 hits:
K.E = (10)(47.432 J)
K.E = 474.32 J
Now, we calculate the heat energy transferred (Q) to the nail. As, it is the 59% of K.E. Therefore,
Q = (0.59)K.E
Q = (0.59)(474.32 J)
Q = 279.84 J
The change in energy of nail is given as:
Q = mCΔT
where,
m = mass of nail = 7.6 g = 0.0076 kg
C = specific heat capacity of aluminum = 900 J/kg.°C
ΔT = Increase in temperature = ?
Therefore,
279.84 J = (0.0076 kg)(900 J/kg.°C)ΔT
ΔT = (279.84 J)/(6.84 J/°C)
ΔT = 40.91 °C
A ball rolls to the right across a grassy field slowing down as it does so. Which of the following must be true?
Answer: i could prolly answer if it made more sense. which of the following where?
Answer:
D: the ball is not accelerating because it is slowing down
Explanation:
if the was no friction, then the ball would most likely pick up speed and never stop, like it would with it being on a hill covered in ice, it would pick up speed and never slow down (well, it would slow down, just at a point where it looks like it would never stop.
In the flowchart representation of the scientific method (the one that embraces the use of constructing models), what does one do immediately after making observations?
Answer:
The correct answer is - ask a question based on observation and then postulate a hypothesis.
Explanation:
The scientific method is the step by step process to find an answer to any scientific question with the help of scientific investigation or experiment. The steps that make an investigation successful are should be in the correct order. These steps are as follows:
*Make an Observation
*Ask a Question
*Do Background Research
*Form a Hypothesis
*Conduct an Experiment
*Analyze Results and Draw a Conclusion
*Report Your Results
Cylindrical rod has equal and opposite forces applied perpendicular to its circular ends. The forces are directed away from the rod, stretching the rod. What type of stress is this rod subject to:_________A) The rod is subject to shear stress. B) The rod is subject to tensile stress. C) The rod is subject to compressive stress. D) The rod is subject to bulk stress.
Answer:
B) The rod is subject to tensile stress
Explanation:
Tensile stress is the force induced in the body per unit area in response to externally applied force, which stretches the body.
Tensile stress is attached with tensile forces. It is makes material elongate along the axis of the applied load.
It is given as magnitude (F) of the force that is applied along an elastic rod divided by the cross sectional area (A) of the rod in a direction that is perpendicular to the applied force.
materials such as Doctile have the ability to withstand the load while brittle materials who not have the ability they fail before reaching the ultimate material strength.
A roller coaster has a vertical loop with radius 29.5 m.What is the minimum speed of the roller coaster car can have at the top of the loop if the passengers do not lose contact with the seats?
A) 10.0 m/s
B) 14.0 m/s
C) 17.0 m/s
D) 19.0 m/s
Answer:the Minimum speed , v of the roller coster = 17.0 m/s --c
Explanation:
According to Newton's First law of Motion which state that all object will remain at rest unless an external force is applied on the body to act otherwise.
Therefore the Force exerted/ acting on the surface of the roller coaster will be equal to 0,
Net Force = 0
Remember that , Force = mg = Mv ²/r = 0
Net Force =mv ² / r - mg = 0
mv²/ r - mg = 0
(diving through by m)
v²/r -g = 0
v² = gr
v= [tex]\sqrt{gr}[/tex]
where g, acceleration due to gravity= 9.8m/s2 and radius, r = 29.5m
v= [tex]\sqrt{9.8m/s2 X 29.5m }[/tex]
v =[tex]\sqrt{ 289}[/tex]
v= 17.0 m/s
Therefore, the Minimum speed , v of the roller coaster = 17.0 m/s
30.6*X+-2.56
Pls help
Answer: 10.16
Explanation:
What is an atom's nucleus made of?
(2 points)
protons and electrons
protons only
protons and neutrons
neutrons only
Answer:
nucleus made of protons and neutrons because the chemical atom is determined my a number
A barrel of oil contains roughly 6.1x109 J. How many kW-hr is this? Answer in
units of kW-hr
Answer:
[tex]1.694*10^3KW/hr[/tex]
Explanation:
Formula:
[tex]KW/hr=E_{(change)}[/tex]
[tex]P=\frac{E}{t}[/tex]
[tex](KW)(s)=1000J[/tex]
[tex](3600)(KW)(s)=3600*1000J[/tex]
[tex]KW=3.6*10^6[/tex]
[tex]\frac{6.1*10^9}{3.6*10^6}=\frac{x}{1KW}[/tex]
[tex]1.694*10^3KW/hr[/tex]
Hope it helps
On Earth, you can lift a 10 kg object. What is the mass of that object on the moon? Is mass independent from gravity?
Explanation:
An object's weight depends on the pull of the gravitating object but the object's mass is independent of the gravity.
1. In a particular experiment to study the photoelectric effect, the frequency of the incident light and the temperature of the metal are held constant. Assuming that the light incident on the metal surface causes electrons to be ejected from the metal, what happens if the intensity of the incident light is increased?A. The work function of the metal decreases. B. The number of electrons emitted from the metal per second increases. C. The maximum speed of the emitted electrons increases. D. The stopping potential increases.2. In another experiment, the intensity of the incident light and the temperature of the metal are held constant. Assuming that the initial light incident on the metal surface causes electrons to be ejected from the metal, what happens if the frequency of the incident light is increased? A. The work function of the metal increases. B. The number of electrons emitted from the metal per second increases. C. The maximum speed of the emitted electrons increases. D. The stopping potential increases.
Answer: 1. B. The number of electrons emitted from the metal per second increases.
2. The maximum speed of the emitted electrons increases.
The stopping potential increases
Explanation:
Photoelectric effect is simply referred to as the emission of electrons that occurs when there's an electromagnetic radiation. An example of such electromagnetic radiation is when material is being hit by light.
Assuming that the light incident on the metal surface causes electrons to be ejected from the metal, the number of electrons emitted from the metal per second increases if the intensity of the incident light is increased.
Also, if the initial light incident on the metal surface causes electrons to be ejected from the metal, the maximum speed of the emitted electrons increases and the stopping potential increases.
