An electrical heating coil is immersed in 4.6kg of water 22°C.The coil, which has a resistance of 250Ω, warms the water to 32°C in 15min. What is the potential difference at which the coil operates?
Answer:
242.4 V
Explanation:
Applying,
Q = cm(t₂-t₁)................ Equation 1
Where Q = amount of heat, c = specific heat capacity, m = mass, t₁ = initial temperature, t₂ = final temperature.
But this heat is produced by electrical power
Therefore,
P = Q/t
Where P = Electrical power, t = time
Also,
P = V²/R
Where V = voltage, R = resistance
Therefore
V²/R = Q/t......................... Equation 2
Substitute equation 1 into equation 2
V²/R = cm(t₂-t₁)/t................. Equation 3
Given: R = 250 ohms, m = 4.6 kg, t₁ = 22°C, t₂ = 32°C, t = 15 min. = (15×60) = 900 seconds
Constant: c = 4600 J/kg.°C
Substitute these values into equation 2
V²/250 = 4600(4.6)(32-22)/900
V²/250 = 235.11
V² = 250×235.11
V² = 58777.78
V = √58777.78
V = 242.4 V
A CAR APPROACHING A SCHOOL ZONE SLOWS DOWN FROM 38 M/S TO 10 M/S AT A CONSTANT ACCELERATION -4 METER PER SEC SQUARE HOW MUCH TIME IS REQUIRED TO SLOW DOWN TO FINAL VELOCITY
Answer:
7 seconds
Explanation:
he went down -28 m/s so 7 times -4 equals -28 m/s which is what he needed to slowness down to 10 m/s
(v) A car
A car is pulled with a force of 60.N at angle of 30 ron, the
horizontal. Find the vertical and horizontal components of the applied
force.
Answer:
Explanation:
The vertical component is found in the magnitude of the force times the sine of the angle; the horizontal component is found in the magnitude of the force times the cosine of the angle. Thus:
vertical component = [tex]60.0sin(30.0)=30.0[/tex] and
horizontal component = [tex]60.0cos(30.0)=52.0[/tex]
A small 175-g ball on the end of a light string is revolving uniformly on a frictionless surface in a horizontal circle of diameter1.0 m.
Complete question:
A small 175-g ball on the end of a light string is revolving uniformly on a frictionless surface in a horizontal circle of diameter 1.0 m. The ball makes 2.0 revolutions every 1.0 s. What are the magnitude and direction of the acceleration of the ball?
Answer:
The acceleration of the ball is 78.98 m/s², directed inwards
Explanation:
Given;
mass of the ball, m = 175 g
radius of the circle, r = 0.5 m
angular speed of the ball, ω = 2 rev/s
The magnitude of the centripetal acceleration of the ball is calculated as follows;
[tex]a_c = \omega^2 r\\\\where;\\\omega \ is \ angular \ speed \ in \ rad/s\\\\a_c = (2\ \frac{rev}{s} \times \frac{2\pi \ rad}{1 \ rev} )^2 \times (0.5 \ m)\\\\a_c =78.98 \ m/s^2[/tex]
The centripetal acceleration is directed inwards.
PLS HELP DUE TODAY
A group of Ontario farmers form a cooperative group and build a factory that turns corn into a fuel for generators and cars. Would this energy source be renewable or non-renewable? Explain.
Answer:
renewable, you can keep growing corn for it. more fossil fuel can be made by nature but it takes way too long to be considered renewable
Having greater or less electrons possessed by an object. Can attract or repel.
A. proton
B. magnetism
C. charge
D.magnet
Answer:
A. Proton
Explanation:
Given that an electron has a net negative charge equal in magnitude to the charge of a proton (1.602 × 10⁻¹⁹) but having an opposite (negative) sign to that of a proton, and given that like charges (negative to negative) repel and unlike charges attract, an object having;
Greater electron will be negatively charged relative to the other object, to which it is compare, which is a proton will attract the (positively charged) proton
Lesser negative charge compared to the proton; therefore, both objects will be positive, and they will repel each other
We therefore have;
Having greater or less electrons possessed by an object. Can attract or repel a proton
The correct option is option A. proton
HELP PLEASE 15 POINTS !!!
True or False. Friction is a non-contact force?
( please answer !! i’ll mark brainliest! )
Answer:
False
Explanation:
Friction is a force exerted by a surface against the motion of a body across its surface. Therefore, friction is a type of contact force only.
A person walks at a speed of 6 km/h from point A to point B. If he improves his pace by 1.5 km/h, he will arrive 1 hour earlier.
a) calculate the distance and time he intends to travel from a to b
b) the individual initially travels at v1=6 km/h for a distance s1, then pauses for 15 minutes to rest. So he goes at v2=7.5km/h for the rest of the route and arrives 30 minutes early than expected.
Answer:
a) The distance is 30 km
The time duration is 5 hours
b) s₁ is approximately 28.142 km or s₁ is approximately 1.505 km
Explanation:
The initial speed with of the person, v₁ = 6 km/h
The distance the walked by the person, d = From point A to point B
The rate at which the person increases the speed, Δv = 1.5 km/h
The time it takes for the person to arrive at point B from point A at the new speed, t₂ = 1 hour earlier than when walking at 6 km/h
a) Let t₁ represent the time it takes the person walking from point A to point B at 6 km/h, we have;
t₂ = t₁ - 1...(1)
d/t₁ = 6...(2)
d/t₂ = 6 + 1.5 = 7.5
∴ d/t₂ = 7.5...(3)
From equation (2), we have;
d = 6 × t₁ = 6·t₁
Plugging in d = 6·t₁, and t₂ = t₁ - 1 in equation (3) gives;
d/t₂ = 7.5
∴ 6·t₁/t₁ - 1 = 7.5
6·t₁ = 7.5 × (t₁ - 1) = 7.5·t₁ - 7.5
7.5·t₁ - 6·t₁ = 7.5
1.5·t₁ = 7.5
t₁ = 7.5/1.5 = 5
t₁ = 5
The time it takes the person walking from point A to point B at 6 km/h, t₁ = 5 hours
The distance from point A to point B, d = 6 km/h × 5 hours = 30 km
b) The distance the person travels at the initial speed, v₁ (6 km/h) = s₁
The duration the person pauses for a rest = 15 minutes = 1/4 hours
The speed with which he walks the rest of the journey, v₂ = 7.5 km/h
The time earlier than expected that he arrives, Δt = 30 minutes = 0.5 hours
We note that the total distance, d = 30 km
The expected time, t₁ = 5 hours
Therefore, we have;
s₁ + s₂ = 30 km
s₂ = 30 - s₁
v₁/s₁ + 1/4 + v₂/s₂ = t₁ - 0.5
Therefore;
6/s₁ + 1/4 + 7.5/(30 - s₁) = 5 - 0.5 = 4.5
6/28.142+ 1/4 + 7.5/(30 - 28.142) = 5 - 0.5 = 4.5
6/s₁ + 7.5/(30 - s₁) = 4.5 - 1/4 = 4.25
-(3·s₁ + 360)/(2·s₁²- 60·s₁) = 4.25
2·s₁²- 60·s₁) × 4.25 + 3·s₁ + 360 = 0
17·s₁²- 504·s₁ + 720 = 0
s₁ = (504 ± √((-504)² - 4 × 17 × 720))/(2 × 17)
s₁ ≈ 28.142 or s₁ = 1.505
The distance the individual travels at v₁ = 6 km/h, s₁ ≈ 28.142 km or 1.505 km
Answer this question fast please
in what state of matter can conduction occur.
Answer: Conduction occurs more readily in solids and liquids, where the particles are closer to together, than in gases, where particles are further apart.
Answer:
conduction occurs when gas becomes liquid.
A riddle for you
In some situations, I oppose the motion
in other situations, I facilitate the motion
but, I always oppose
the relative motion
between two moving surfaces.
Put some lubricant, and
I become small there.
Make the moving surfaces rough
I make the movement tough.
I may be
static, sliding or rolling
but whenever two surfaces are in motion
I am always there,
Tell me who I am!
The person who answers it correctly will be marked as brainlist
Answer:
The Answer is FRICTION!
A book with a mass of 2 kg sits on top of a book shelf at a height of 3 m. How much potential energy does the book have
Answer:
Answer is 98 joules
Explanation:
P. E=2*9.8*3=98
S.i unit of potential energy ⚡ is joules
So answer is 98 joules
What is the purpose of the circuit breaker in your home?
To provide electricity to all of the electrical devices in your home.
To maximize the electrical efficiency of appliances plugged in.
To prevent too much current from traveling into the circuit, making the wire hot and starting a fire.
To irritate the %$&* out of you when they turn off.
Answer:
to prevent to much current
Explanation:
in the event of a power surge the circuit breaker will cut the power. this is what people mean when they say "pop" the breaker
difference between local system and si system
Answer:
In antiquity, systems of measurement were defined locally: the different units might be defined independently according to the length of a king's thumb or the size of his foot, the length of stride, the length of arm, or maybe the weight of water in a keg of specific size, perhaps itself defined in hands and knuckles.
Systems of Measurement: there are two main systems of measurement in the world: the Metric (or decimal) system and the US standard system. ... The US Standard system uses units that have no predictable relationship to each other. For example, there are 2 cups in a pint, but 4 quarts in a gallon.
Find the force due to a current element of length 6cm and flux density of 12 tesla. The current through the element will be 10A.
Answer:
7.2 N
Explanation:
Applying,
F = BIL................. Equation 1
Where F = Force due to current through the element, B = magnetic field, L = Length of the element.
From the question,
Given: B = 12 Tesla, L = 6 cm = 0.06 m, I = 10 A
Substitute these values into equation 1
F = 12(0.06)(10)
F = 7.2 N
Hence the force through the element is 7.2 N
Select all the correct answers. Which statements about potential energy are true?
Answer: The statement gaining potential energy is always associated with a force field, is true about potential energy.
Explanation:
The energy acquired by an object due to its position is called potential energy.
Basically, a force field exerts a force that gives rise to potential energy of an object. For example, gravity, spring force etc.
This means that gaining potential energy is always associated with a force field.
A change in position does not always means that an object gains potential energy. For example, a spring will have more potential energy when it is compressed or stretched.
Hence, change in position of an object not necessarily means always gain in potential energy.
There are two types of potential energy that is, gravitational potential energy and elastic potential energy.
Thus, we can conclude that the statement gaining potential energy is always associated with a force field, is true about potential energy.
Answer:
Explanation:
The first one and the last one are the correct answer.
Why are circuit breakers and fuses important?
1)They help regulate the voltage drop in a power source.
2)They help insulate live wires to prevent shocks.
3)They help prevent electrical accidents.
4)They help current flow smoothly.
Answer:
option 3, as circuit breakers are mostly used as precautions
suggest and explain the modifications that need to be done on the galvanometer to increase its sensitivity.
Answer:
So, sensitivity of the galvanometer can be increased either by increasing the number of turns (N), using strong magnets or increasing the area of the coil (A). So, the correct answer is that the sensitivity of a moving coil galvanometer can be increased by increasing the number of turns of the coil.
I need help with this science question, 50 points!
Answer:
an open circuit (A battery, bulb, wire,switch)
Explanation:
the battery supplies the power the wire carries the current from the battery to the bulb but the circuit is not completed if the switch is not connected (Switch )
A hippopotamus laying on the rock exerts 10,000 N on the rock. The rock has a mass of
2 tons. How much work is being done? Be sure to show your work.
Answer:
Explanation:
If the hippo is laying on the rock, I'm assuming that there is no movement going on at all, in either the hippo or the rock. If no movement occurs, there is no work being done.
man start to moves from point A (Initial Point) to Point B (Final Point) in a given
figure. Find the Distance and Displacement from the given Figure :-
(2)
Answer:
Image not full.
Explanation:
From what I can see, Displacement is 175m,
Distance will be = 100 + 50 + the hidden value on the bottom right
6. A ball rolled 125 m from the top of a hill to the bottom of a hill. How long
did it take for the ball to roll if the average velocity was 5m/s? *
Ponds and lakes are part of marine ecosystem.
True or false ?
Answer:
True
Explanation:
because they can hold marine organism inside
The process of making alloys involves
Answer:
The process of making alloys involves ( Heating ) pure metals to remove impurities. Then the pure metals are(mixed) with other components. An alloy is a mixture of metals or a mixture of a metal and another element. Alloys are defined by a metallic bonding character.
Explanation:
Which of the following physical quantity is having same SI units?
a) Speed and average speed
b) Speed and velocity
c) Speed and average velocity
d) All the above
Answer:
d) All the above
Explanation:
Speed SI unit is metre per second.Velocity SI unit is metre per second.Average speed SI unit is metre per second.Average velocity SI unit is metre per second.Therefore, as all of the physical quantities have the same SI units, the answer is d) all of the above.
An object falling straight down without air resistance is said to be exhibiting
A. free fall
B. projectile motion
C. circular motion
D. two-dimensional motion
Answer:
Explanation:
If the object is falling straight down it is in free fall. The difference between that and two-dimensional motion is that 2D motion is parabolic (projectile)
1. 10. waves break on the beach in 2.0 min. What is the frequency in hertz of these waves (cycles per
second)? What is the time between successive waves, in seconds?
Answer:
there it is fella tried o. ma own consciousness
is James Charles a boy or a girl ? I am so confused
Answer:
both
Explanation:
and I'm serious he is literally both
why does pressure on Diver increases with depth?
Answer: the pressure increases with the amount of water pushing in on all sides of the diver, for example, when you jump into a pool and you head is above water it a little harder to breathe, it is the same way for divers when they are diving at increasingly deep depths, the deeper you are the more water is pressing in on you.
Explanation:
