A kettle transfers 1,500 J of energy, 1,200 J to a thermal energy store and 300 J to a vibrational energy store (sound). How efficient is the kettle?
Answer:
[tex]\eta = 0.8 = 80\%[/tex]
Explanation:
Efficency of a machine is defined as the ratio of "useful" energy over the total energy imput in it. In this case a kettle wants to heat water, so thermal energy is what we need; if we wanted to build some kind of music instrument, we would be looking at the energy generating vibrations.
[tex]\eta = \frac{1200J}{1500J} = 0.8[/tex]
7. A car is
speeding up
with a force of
a
120 N, heading
East. The
force of
friction acts
against the car
with a force of
80 N West.
What is the net
force?
Answer:Fricition
Explanation: It is fricition in the net force
A car is speeding up with a force of 120 mph and heading east. The force of friction acts against the car with a force of 80 N westward, and the net force acting on the car is 40 N eastward, which means the car is accelerating eastward with a force of 40 N.
What is the calculation of net force?To calculate the net force acting on the car, one needs to consider the direction and magnitude of the forces acting on it. A force of 120 N to the east is acting to accelerate the car in that direction, and a force of 80 N to the west is acting to oppose the motion of the car.
Net force = force of acceleration -force of friction.
Net force = 120 N east- 80 N west.
Net force = 40 N East
Hence, the net force acting on the car is 40 N eastward, which means the car is accelerating eastward with a force of 40 N.
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What is the name of a hypothesis that has passed the test of many experiments and has support of other scientists
Answer: Scientific Hypothesis
Explanation: A scientific hypothesis is something supported or approved by a line of scientists through experiments and close observations.
The length of a certain wire is kept same while its radius is doubled. What is the new resistance of this wire
Answer:
R = K L / A resistance proportional to length and inversely proportional
to area
R2 / R1 = A1 / A2 = A1 / (4 A1) = 1 / 4
R2 = R1! / 4
1) In which of these examples is the greatest movement occurring? A) A B) B C) C D) D
Answer:d
Explanation:
According to Boyle's law, as volume decreases, pressure ____________ , and as volume increases, pressure ____________ .
Answer:
In chemistry, according to Boyle's law it tells us that the pressure and volume of an ideal gas are inversely proportional. The pressure has an inverse relationship with the volume. As the volume increases two times, then the pressure of the gas decreases two times.
Explanation:
when drawing a scatter diagram, along which axis is the explanatory variable placed? along which axis is the response variable placed?
how far from the base of the cliff would the driver have landed if the driver initially had been moving horizontally with speed 10 m/s?
Answer:
C
Explanation:
y0=100 m
y=0
x0=0
x=?
v0x=10 m/s (moving horizontally)
v0y=0
x=x0+v0xt
x=10t
y=y0+1/2at^2
solve for t
0=y0-1/2gt^2
(a is acceleration which is - gravitational acceleration )
t=[tex]\sqrt{\frac{2y0}{g} }[/tex]
plug into x equation
x=10([tex]\sqrt{\frac{2y0}{g} }[/tex]) where y0=100m and g=9.80 m/s^2
x= 45.2 m
if you check the distance when v0=5 m/s, we get x=22.5 m so the equation is correct. however if the g your class uses is 10.00 m/s^2, then we get x=22.4 for the first velocity and 44.7 for the second velocity
whats the two factors that determine the amount of kinetic energy
Answer: mass and speed.
Explanation: The two main factors that affect kinetic energy are mass and speed. Why? Because the motion of an object depends on how fast it's traveling.
What is the net force on a water bottle?
Answer:
if it is not moving it is zero, like all things that aren't in motion
Explanation:
Answer:
Note that net force on the bottle is zero.
Explanation:
QUESTION 1:
What orbital pattern do the planets follow?
A circular
B elliptical
C rectangular
Answer:
Planets generally follow elliptical orbits.
The eccentricity describes the ellipticity of the orbit, that is, the departure of an orbit from a circular orbit.
Which of the following statements supports the claim that a planet travels around a star in an elliptical orbit? (1 point)
Every 30 days, the area swept in space by the planet is the same.
Every 30 days, the distance traveled by the planet is different.
Every 30 days, the speed the planet is moving is different.
I only
I and II
II and III
I, II, and III
Answer:
A
Explanation:
if it was in the same place it wold be a pattern which is what is usually seen in orbits
Question 10..help me
Answer:
Go to high ground, as high as possible.
when primary colors are mixed together, they create what?
Answer:
secondary colours yeah
Question 11 (5 points)
If a force of 10.8 newtons is applied to an object that has a mass of 4.6 kg, what will
be the object's acceleration?
*Include ABBREVIATED units in your answer
*Round your answer to 1 decimal place
Answer:
2.3 m/s2
Explanation:
F = ma
a = F/m
a = 10.8 / 4.6
a = 2.3 m/s2
I hope this helps.
How much force is needed to accelerate a. 15 kg mass at 20 m/s2.
Answer:
F = 300 N
Explanation:
This is an example of Newton's second Law
F = m * a
F = ?
m = 15 kg
a = 20 m^2
F = 20 * 15
F = 300 Newtons.
If the 10v battery were replaced by a 15v battery would the current through the 70-ohm resistor increase decrease or remain the same?
Answer:
I think it would increase sorry if I'm wrong
A block weighing 10 newtons is on a ramp inclined at 30° to the horizontal. A 3-newton force of friction acts on the
block as it is pulled up the ramp at a constant velocity. The force applied to pull the box up the ramp acts parallel to the
incline. Draw the FBD for this problem and determine the magnitude of the force applied.
The force applied to pull the box up the ramp acts parallel to the incline is 8N
The force applied to pull the box is expressed as:
[tex]F_N = F_m + F_f[/tex]
Fm is the moving force
Ff is the force of friction
Get the moving force and frictional fice
[tex]F_m = 10sin30^0 = 5N\\F_f = 3N[/tex]
The force applied to pull the box up the ramp acts parallel to the incline = 5N + 3N = 8N
Hence the force applied to pull the box up the ramp acts parallel to the incline is 8N
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A 800 Kg car and driver accelerates at a rate of 35 m/s/s. What force is necessary to bring the car to a complete stop?
Answer:
Your answer would be 28,000 N (newtons).
Explanation:
We'd simply get this by using the formula:
force = mass × acceleration
The information that we have from the question is that the force is 800 times 35.
Now, all we have to do is multiply 800 by 35, and we have our answer of 28,000 N.
I hope I helped, and a Brainliest is always appreciated! ☺
a car traveling at 60m/s accelerates at 2 m/s for 30s.calculate how far it has traveled during this time
Answer:
2,7 km
Explanation:
You should remember from theory that
[tex]s=s_0 + v_0\Delta t + \frac12 a(\Delta t)^2[/tex]. Let's substitute values, remembering that we are interested in the difference in position [tex]\Delta s = s-s_0[/tex]
[tex]\Delta s = 60(30) +\frac12 2 (30)^2 = 2700m[/tex]
Answer:
it's average acceleration is 12 mph
5 differences between mass and weight
Answer:
The mass is essentially "how much stuff" is in an object. ... Weight: There is a gravitational interaction between objects that have mass. If you consider an object interacting with the Earth, this force is called the weight. The unit for weight is the Newton (same as for any other force)
Explanation:
Sebastián midió un trozo de plástico en un momento donde la temperatura era alta, y luego a la noche volvió a medir y no medía lo mismo. ¿Qué pasó?
English:
The piece of plastic most likely cooled.
/
Español:
Lo más probable es que la pieza de plástico se haya enfriado.
A charged particle of mass m and charge q moving in an electric field e has an acceleration a given by , where q and e are constants. Find.
The acceleration of the particle at the given charge, electric field and mass is [tex]\frac{qE}{m}[/tex].
The given parameters;
mass of the particle, = mcharge of the particle, = qelectric field, = EThe acceleration of the particle is calculated as follows;
Newton's second law : F = ma
Coulomb's force: F = qE
Equate the two forces as follows;
[tex]ma = qE\\\\a = \frac{qE}{m}[/tex]
Thus, the acceleration of the particle at the given charge, electric field and mass is [tex]\frac{qE}{m}[/tex].
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Calculate the maximum height a ball reaches when thrown straight up at a velocity of 10m/s
Answer:
5.1m
Explanation:
Use the fourth key equation of accelerated motion
vf^2=vi^2+2aΔd
we know vf is = 0 because that is when the ball reaches it's peak (not going up anymore)
0=vi^2+2aΔd
and we can rearrange for Δd, which is what you need
-vi^2=2aΔd
Δd = -vi^2/2a
Now we can plug in the values
Δd = -vi^2/2a
Δd = -(10m/s)^2/2(-9.8)
Δd = -100/-18.6
Δd = 5.10m
Giải câu 2 của bài tập trên
Answer:
LETTER C IS THE ANSWER
Explanation:
this is my answer
A net force of magnitude 0.6 at on a body of mass 40g intially at rest. calculate the magnitude of the resulting acceleration
→ 0.6 N = 0.04 kg × a
→ 0.6 kg.m/s² ÷ 0.04 kg = a
→ 15 m/s² = a
Therefore, tha magnitude of resulting acceleration is 15 m/s².
Can you please help the question is in an attatchment
Answer:
b because it's b so pick b
A light bulb is basically a resistor that gets so hot that it glows, emitting light. For this tutorial we will assume the resistor in the light bulb is ohmic (that means Ohm's law applies to the resistor). The rate of energy emitted by the light bulb is its output power, commonly referred to as luminosity (brighter means more luminous). Hook up a light bulb to a 5-V battery. Right-click (or control-click) on the light bulb, and change its resistance. How does the brightness of the light bulb depend on its resistance?
A. The brightness of the light bulb is independent of its resistance. It only depends on the voltage of the battery.
B. The light bulb gets brighter as the resistance is increased.
C. The light bulb gets dimmer as the resistance is increased.
Answer:
b
Explanation:
how much energy is needed to heat 2kg of cooking oil with a specific heat capacity of 2000j/kg°c from 20°c to 120°c
Answer:
400kj
Explanation:
h =mass × specific heat capacity × change in temperature
= 2×2000×[120-20]
=2×2000×100
=400000j
=400kj
400kj of energy is needed.
Energy:Energy, which is observable in the execution of labor as well as in the form of heat and light, is the quantitative quality that is transferred to a body or to a physical system in physics. Energy can be transformed in form but cannot be created or destroyed, according to the rule of conservation of energy. The joule, which is the energy supplied to an object by the labor of moving it a distance of one meter against a force of one newton, is the unit of measurement for energy in the International System of Units (SI).Cooking oil:Cooking oil is a liquid fat made of plants, animals, or synthetic materials that are used in baking, frying, and other cooking processes. It may also be referred to as edible oil because it is used in cold food preparation and flavoring, including salad dressings and bread dips.At room temperature, cooking oil is normally a liquid, although some saturated-fat oils, such as coconut oil, palm oil, and palm kernel oil, are solids.Solution -Formula - h = mass × specific heat capacity × change in temperature
So,
[tex]2[/tex] × [tex]2000[/tex] × [tex][120-20][/tex]
[tex]2[/tex] × [tex]2000[/tex] × [tex]100[/tex]
[tex]=400000j\\=400kj[/tex]
Therefore, 400kj of energy is needed.
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an object that covers more distance in the same amount of time has a higher speed.
true or false
Answer:
true
Explanation:
Answer: its true btw :(
