Answer:
The expansion and contraction of materials can also cause problems. For example, bridges expand in the summer heat and need special joints to stop them bending out of shape.A bimetallic strip has two metal strips glued together. One of these metals expands more for each degree temperature rise than that other.
hellllp me please anyone help Light travels from a region of air into a region of air, making an angle of incidence of 60 degrees. Which of the following best describes the path of the light as it moves into the air? A) The light will bend toward the normal B) The light will bend away from the normal C)The light will continue without bending D)The light will move in some manner not determined by the information here.
Answer:
(B)
Explanation:
Because what ever angle the surface is, the light will reflect of of it perpendicular.
as a motorcycle takes a sharp turn the type of motion that occurs is called ——— motion
Answer:
circular motion
Explanation:
hope this helps you :)
Answer:
Centripetal motion
Explanation:
As a motorcycle takes a sharp turn the type of motion that occurs is called centripetal motion
A broom with a long handle balances at its centre of gravity as shown in the figure. If you cut the broom into two parts through the centre of gravity and then weigh each part, which part will weigh more? a) The part with the broom will weigh more. b) The part without the broom will weigh more c) Both the parts will weigh the same d) It would depend on the weight of the broom
Answer:
c) Both the parts will weigh the same
Explanation:
center of gravity is based on weight so if you cut down the center of gravity you would have 2 equal parts
(might be D if it is cutting against the center of gravity)
A gas occupies a volume of 1.0 m3 in a cylinder at a pressure of 120kPa. A piston compresses the gas until the volume is 0.25m3, the temperature remaining constant. What is the new pressure of the gas?
Answer:
Approximately [tex]480\; \rm kPa[/tex], assuming that this gas is an ideal gas.
Explanation:
Let [tex]V(\text{Initial})[/tex] and [tex]P(\text{Initial})[/tex] denote the volume and pressure of this gas before the compression. Let [tex]V(\text{Final})[/tex] and [tex]P(\text{Final})[/tex] denote the volume and pressure of this gas after the compression.By Boyle's Law, the pressure of a sealed ideal gas at constant temperature will be inversely proportional to its volume. Assume that this gas is ideal. By this ideal gas law:
[tex]\displaystyle \frac{P(\text{Final})}{P(\text{Initial})} = \frac{V(\text{Initial})}{V(\text{Final})}[/tex].
Note that in Boyle's Law, [tex]P[/tex] is inversely proportional to [tex]V[/tex]. Therefore, on the two sides of this equation, "final" and "initial" are on different sides of the fraction bar.
For this particular question:
[tex]V(\text{initial}) = 1.0\; \rm m^3[/tex].[tex]P(\text{Initial}) = 120\; \rm kPa[/tex].[tex]V(\text{final}) = 0.25\; \rm m^3[/tex].The pressure after compression, [tex]P(\text{Final})[/tex], needs to be found.Rearrange the equation to obtain:
[tex]\displaystyle P(\text{Final}) = \frac{V(\text{Initial})}{V(\text{Final})} \cdot P(\text{Initial})[/tex].
Before doing any calculation, think whether the pressure of this gas will go up or down. Since the gas is compressed, collisions between its particles and the container will become more frequent. Hence, the pressure of this gas should increase.
[tex]\begin{aligned}P(\text{Final}) &= \frac{V(\text{Initial})}{V(\text{Final})} \cdot P(\text{Initial})\\ &= \frac{1.0\; \rm m^{3}}{0.25\; \rm m^{3}} \times 120\; \rm kPa = 480\; \rm kPa\end{aligned}[/tex].
What is electrical power in terms of current and potential difference? Explain.
Answer:
Ohm's Law:
[tex]V = IR[/tex]
Where V is voltage, I is current and R is resistance
While,
[tex]P = IV[/tex]
Where P is power, I is current and V is voltage (or potential difference)
So, Electrical power is the product of current and potential difference.
A 1500kg car accelerates from 50km/h to 75km/h. How much work was done?
Answer:
Work done, W = 181238.4 J
Explanation:
We have,
Mass of a car, m = 1500 kg
Initial speed, u = 50 km/h = 13.88 m/s
Final speed, v = 75 km/h = 20.84 m/s
Let W is the work done. It is equal to the change in kinetic energy of the car. So,
[tex]W=\dfrac{1}{2}m(v^2-u^2)\\\\W=\dfrac{1}{2}\times 1500\times ((20.84)^2-(13.88)^2)\\\\W=181238.4\ J[/tex]
So, 181238.4 J of work was done by the car.
One sprinter has a stride of 120cm, another 75cm. How many steps do they each take if they run a 100m race?
Explanation:
100 m / (1.20 m) = 83.3
100 m / (0.75 m) = 133.3
Rounded up, the first sprinter takes 84 steps, and the second sprinter takes 134 steps.
Explain the concept of "charge" and how it relates to electricity?
Answer:
An Electric "charge" is a property of matter that causes a force to repel or attract when placed into a magnetic field. These charges can be replicated into positive and negative electrons when made from a chemical reaction.
Answer:
an electri
Explanation:
Three 15.0-W resistors are connected in parallel across a 30.0-V battery. Please show all work.
a) Find the current through each branch of the circuit.
b) Find the equivalent resistance of the circuit.
c) Find the current through the battery.
Answer:
Part A)
Since all of the resistors have equal resistance, hence for finding even only 1 branch It will be fine because current will be the same for all branches.
=> [tex]I = \frac{V}{R_{1} }[/tex]
=> [tex]I = \frac{30}{15}[/tex]
=> I = 2 A
Part B)
Equivalent resistance for parallel circuits is the sum of reciprocals of each resistor.
=> [tex]\frac{1}{R} = \frac{1}{R_{1}}+\frac{1}{R_{2}} +\frac{1}{R_{3}}[/tex]
=> [tex]\frac{1}{R} = \frac{1}{15}+ \frac{1}{15}+\frac{1}{15}[/tex]
=> [tex]\frac{1}{R} = \frac{3}{15}[/tex]
=> R = 15/3
=> R = 5 ohms
Part C)
I = V/R
Where I is current, V is voltage and R is the equivalent resistance
=> I = 30/5
=> I = 6 A
Find the electric field a distance z above a circular ring carrying a constant line charge. For extra credit you may derive the electric field a distance z above a disk carrying a constant surface charge density. 3 Find the force between an electron and a proton in a typical hvdrogen atom.
Answer:
F = 8.23 × 10⁻⁸N
Explanation:
F= kq²/r²
k= 9×10⁹Nm²/C²
q= 1.6×10⁻¹⁹C
r= 5.29×10⁻¹¹m
F= 9×10⁹× (1.6×10⁻¹⁹)²/ (5.29×10⁻¹¹)²
F = 8.23 × 10⁻⁸N
A vehicle traveling on wet or slick roads can begin to _________ as water forms a barrier between the road and the tires and traction is lost as the wheels start to ride on top of the water and not the road surface. a) skid b) hydroplane c) lose traction d) splash water on to the engine
Answer: B.) HYDROPLANE
Explanation: The term hydroplane can be used to refer to a condition which usually occur during a downpour or on surfaces covered by water. It occurs when water forms a barrier or comes in between the frictional grip which occurs between the road surface and the car tyres. The contact between the car tyres and the road surface is supposed to give adequate frictional support which prevents the car from skidding or skidding uncontrollably on the road surface. However, when water comes invetween the surface, traction is lost and skidding results due to very low Coefficient of friction between the road and Tyre which was supposed to provide a firm grip between the tyres and the road surface.
When a vehicle is traveling on wet or slick roads, hydroplaning can occur. The correct answer is b) hydroplane.
When a vehicle is traveling on wet or slick roads, hydroplaning can occur. Hydroplaning happens when a layer of water builds up between the tires of the vehicle and the road surface, leading to a loss of traction.
This loss of traction can cause the vehicle to skid or slide, making it difficult to control. The tires ride on top of the water rather than maintaining contact with the road, resulting in reduced traction and control of the vehicle.
Therefore, When a vehicle is traveling on wet or slick roads, hydroplaning can occur. The correct answer is b) hydroplane.
To know more about hydroplaning:
https://brainly.com/question/33723980
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*SS2 E_CAT 2020*
*DATE:* FRIDAY, 3RD JULY 2020
*Time allowed:* 40 minutes
*Instruction*: Attempt all questions. Send screenshots of solutions to my number *privately*.
*Take:* specific heat capacity of water = 4200 J/kgK
1. The lower and upper fixed points of a mercury-in-glass thermometer are marked X and 180mm respectively. On a particular day, the mercury meniscus in the thermometer rises to 60mm. If the corresponding reading on a Celsius scale is 20°C, what is the value of X?
2. A resistance thermometer has a resistance of 20 ohm at 0°C and 85 ohm at 100°C. If its resistance is 52 ohm in a medium, calculate the corresponding temperature.
3. A tap supplies water at 26°C while another supplies water at 82°C. If a man wishes to bath with water at 40°C, what is the ratio of the mass of hot water to that of cold water.
4. A metal of mass 1.55kg was heated from 300K to 320K in 6 minutes by a boiling ring of 85 W rating, calculate the specific heat capacity of the metal. {Neglect heat losses to the surrounding.}
5. (i) What is meant by the statement, _the specific heat capacity of copper is 400 J/KgK? (ii) Distinguish between specific heat capacity and thermal capacity deriving the mathematical relationship between.
thank you
Explanation:
2. Heat gained by tap1 = mass1 × SHC × change in temperature
= mass1 × 4200 × (40 - 26)
= mass1 × 58800
Heat lost by tap 2 = mass2 × SHC × change in temperature
= mass2 × 4200 × (82 - 40)
= mass2 × 176400
Heat gained = heat lost
mass1 × 58800 = mass2 × 176400
Ratio of mass 1 to mass 2 = 58800mass1 : 176400mass2
= 1 : 3
How is mercury barometer constructed ?
Answer:
A mercury barometer is a device use to measure stomspheric pressure and is constructed as following:
A mercury barometer requires a tube which has one close end, and one open end.Tube is placed upside down in a beaker in such a way so that one end open in the beaker and the other remain outside of the beaker. The barometric liquid (mercury) is then filled in the tube by pouring mercury liquid in the beaker.The position of tube creates vacuum between the closed end of the tube and liquid surface and the Mercury has high density that is why used as the liquid to measure pressure.
PLEASE I NEED HELP WITH THIS ASAP
A student finds a rock on the way to school. In the laboratory he determines that the volume of the rock by placing the rock in a graduated cylinder with 50 cm3 of water and watched the water rise to 72.7 cm3. The student determined the mass is 39.943 g through the use of a triple beam balance. What is the density of the rock?
With step by step explanation
Answer:
density=mass/volume
39.943/22.7=1.75
Explanation:
I NEED HELP PLEASE, THANKS! :)
The electric field around a positive charge is shown in the diagram. Describe the nature of these lines.
Answer:
They move outwards.
They don't intersect each other at any point.
They show the electric field.
Explanation:
Answer:
Please read the answer below
Explanation:
the nature of these lines refers to the fact that positive charges generate field lines that are directed out of the positive charges, and in turn are directed towards some negative charge present somewhere in the universe.
By consensus, the electric field lines leave the positive charges and enter the negative charges. That is the reason why in a scheme like the shown in the image, is considered implicitly the existence of a negative charge, in some place of the universe.
Select the correct the answer.
What do the circled arrows in the image indicate?
A. CO2 absorbed by the atmosphere
B. CO2 released to the atmosphere
C. oxygen absorbed by the atmosphere
D. oxygen released by the atmosphere
Answer:
it shows that co2 is absorbed by the atmosphere.
when the animals respire they produce co2 which is release in atmosphere and in presence of sunlight and chlorophyll the plants manufacturs the food and releases the oxygen in the atmosphere .
hope it helps..
Answer:
Its A
Explanation:
An object in a certain direction with an acceleration in the perpendicular direction
Answer:
An object moving in certain direction with an acceleration in the perpendicular direction. The above condition is possible . Example of such situation in life would be when stone tied to a string whirling in a circular path
Hope this helps and pls mark as BRAINLIEST :)
Un resorte se alarga 5 cm bajo la acción de una fuerza de 39,2 N. ¿Cuál es la constante del resorte? Si ahora la fuerza es 68,6 N. ¿Cuál es el nuevo alargamiento?
Answer:
[tex]k=784 N/m[/tex]
[tex]\Delta x=8,8 cm[/tex]
Explanation:
Usando la ley de Hook tenemos:
[tex]F=k\Delta x[/tex]
Solving it for k we have:
[tex]k=\frac{F}{\Delta x}[/tex]
[tex]k=\frac{39,2}{0,05}[/tex]
[tex]k=784 N/m[/tex]
Usando la misma ecuación y sabiendo k tenemos:
[tex]\Delta x=\frac{F}{k}[/tex]
[tex]\Delta x=\frac{68,6}{784}[/tex]
[tex]\Delta x=8,8 cm[/tex]
Espero esto te ayude!
2. Find the time taken by the bus to reach the stop. need only group B, 2 answer
Answer:
t = 2 seconds
Explanation:
In 2nd question, the question is given the attached figure.
Initial speed of the bus, u = 0
Acceleration of the bus, a = 8 m/s²
Final speed, v = 16 m/s
We need to find the time taken by the car to reach the stop. Acceleration of an object is given by :
[tex]a=\dfrac{v-u}{t}[/tex]
t is time taken
[tex]t=\dfrac{v-u}{a}\\\\t=\dfrac{16-0}{8}\\\\t=2\ s[/tex]
The bus will take 2 seconds to reach the stop.
pls help, me, i nees to submit now
Answer:
12m
Explanation:
To obtain the answer to the question given, we must observe the characteristics of image formed by a plane mirror.
The image formed by a plane mirror have the following characteristics:
1. Laterally inverted.
2. Same distance as the object from the mirror.
3. Same height as the object.
4. Virtual.
With the above information, we can calculate the distance between the boy and his image as follow:
Initially:
Object distance (u) = 4m
Image distance (v) = 4m
The boy moved 2m away, therefore:
Object distance (u) = 2 + 4 = 6m
Image distanc(v) = 2 + 4 = 6m
The distance between the boy and his image will be the sum of his distance (u) and image distance (v) i.e (u + v)
The distance between the boy and his image = 6 + 6 = 12m
Therefore, the distance between the boy and his image is 12m.
a body starts from rest and gains the velocity of 5 metre per second into second is it of uniform velocity explain
Answer:
It is not a uniform velocity, because his velocity increases for 5 m every second (acceleration = 5m/s2), meaning his velocity always changes.
When he starts at rest, his velocity is 0 m/s. But in 1 second later, his velocity is already 5m/s. At 2 seconds, his velocity will be 10 m/s.
At one point in the rescue operation, breakdown vehicle A is exerting a force of 4000 N and breakdown vehicle B is exerting a force of 2000 N.(i) Using a scale of 1 cm = 500 N, make a scale drawing to show the resultant force on the truck. (ii) Use your diagram to find the magnitude and direction of the resultant force on the truck.
Answer:
1.) Magnitude = 5596 N
2.) Direction = 60 degrees
Explanation: You are given that the breakdown vehicle A is exerting a force of 4000 N at angle 45 degree to the vertical and breakdown vehicle B is exerting a force of 2000 N
Let us resolve the two forces into X and Y component
Sum of the forces in the X - component will be 4000 × cos 45 = 2828.43 N
Sum of the forces in the Y - component will be 2000 + ( 4000 × sin 45 )
= 2000 + 2828.43
= 4828.43 N
The resultant force R will be
R = sqrt ( X^2 + Y^2 )
Substitutes the forces at X component and Y component into the formula
R = sqrt ( 2828.43^2 + 4828.43^2 )
R = sqrt ( 31313752.53 )
R = 5595.87 N
The direction will be
Tan Ø = Y/X
Substitute Y and X into the formula
Tan Ø = 4828.43 / 2828.43
Tan Ø = 1.707106
Ø = tan^-1( 1.707106 )
Ø = 59.64 degree
Therefore, approximately, the magnitude and direction of the resultant force on the truck are 5596 N and 60 degree respectively.
A car of mass 800 kg is moving at a uniform velocity of 72 km/hr. Find its
momentum.
[Ans: 16000 kgm/s)
A body of mass 5 kg has momentum of 125 kg m/s. Find the velocity of the body
in motion.
[Ans: 25 mls)
Answer:
hope its helpful to uh...
Modifiable strength improvement factors include all of the following except...??
Answer:
Muscle size and training specifiicty
Explanation:
It depends on all other factors such as anatomy and psychology, muscle fiber recruitment, motor pattern development and muscle memory but to increase modifiable strength, size plays no big role.
The count rate of a radioactive source decreases from 1600 counts per minute to 400 counts per minute in 12 hours. What is the half-life of the source?
Answer:
[tex]t_{1/2}=6 h[/tex]
Explanation:
Let's use the decay equation.
[tex]A=A_{0}e^{-\lambda t}[/tex]
Where:
A is the activity at t timeA₀ is the initial activityλ is the decay constantWe know that [tex]\lambda=\frac{ln(2)}{t_{1/2}}[/tex]
So we have:
[tex]\lambda=\frac{ln(A/A_{0})}{t}[/tex]
[tex]\frac{ln(2)}{t_{1/2}}=\frac{ln(A/A_{0})}{t}[/tex]
[tex]t_{1/2}=\frac{t*ln(2)}{ln(A/A_{0})}[/tex]
[tex]t_{1/2}=6 h[/tex]
Therefore, the half-life of the source is 6 hours.
I hope it helps you!
A boy is twirling a model airplane on a string 4 feet long. if he twirls the plane at 0.25 revolutions per minute, how far does the plane travel in 4 minutes? round to the nearest tenth.
Answer:
25.13 ft
Explanation:
r = 4 feet
ω=0.25 revolution per minute
=1 revolution in 4 minutes
total number of revolution N = 1 (in 4 minutes )
v=rω
distance traveled = 2×N×π×r
=2×1×π×4
=8π
= 25.13ft in 4mins
Before beginning an experiment, Mrs. Wilson warns her science class not to drop the bar magnets on the floor. What is the most likely reason for Mrs. Wilson’s warning?
Answer:
we should not drop a magnet on the floor because the magnets tend to lose magnetism gradually and become weak over a period of time if they are not stored properly.
Answer:
Well depending on the floor like say if it was a wooden floor the magnet might lose it magnetism, if concrete floor the magnetic brake and still lose it magnetism, if a metal floor the magnet would stick not sure if it wood lose it magnetism or not but the possibilities still there, basically what I'm saying is the magnet would lose its magnetism if it were to interact with the floor maybe temporary or maybe permanently.
for those with with a learning disability it's a
Explanation:
This equation is missing which motion variable?
Answer:
Option A. a
Explanation:
Motion variables include:
1. Final velocity (vf).
2. Initial velocity (vi).
3. Time (t).
4. Acceleration (a)
5. Distance (x)
Considering the equation given in the question:
Δx = ½(vf + vi) t
We can see that the acceleration (a) is missing in the equation.
the most common mineral group is broken into the subgroups of ferromagnesium and nonferromagnesium
Answer:
They're made of silicon and oxygen.
Explanation:
With an initial velocity of 9.8 m / sg, an object is thrown upwards from the roof of a 100 m high building. Determine maximum height from the ground, time it takes to reach the ground, and the speed with which it reaches the ground.
Answer:
104.9 m
5.63 s
45.3 m/s
Explanation:
Given:
y₀ = 100 m
v₀ = 9.8 m/s
a = -9.8 m/s²
Find: y when v = 0 m/s
v² = v₀² + 2a (y − y₀)
(0 m/s)² = (9.8 m/s)² + 2 (-9.8 m/s²) (y − 100 m)
y = 104.9 m
Find: t when y = 0 m
y = y₀ + v₀ t + ½ at²
0 m = 100 m + (9.8 m/s) t + ½ (-9.8 m/s²) t²
0 = 100 + 9.8t − 4.9t²
t = [ -9.8 ± √(9.8² − 4(-4.9)(100)) ] / 2(-4.9)
t = (-9.8 ± 45.3) / -9.8
t = 5.63 s
Find: v when y = 0 m
v² = v₀² + 2a (y − y₀)
v² = (9.8 m/s)² + 2 (-9.8 m/s²) (0 m − 100 m)
v = -45.3 m/s
|v| = 45.3 m/s