Answer:
Final temperature, T2 = 31.11°C
Explanation:
Given the following data;
Mass = 4.5kg
Initial temperature = 20°C
Quantity of heat = 90000J
Specific heat capacity = 1,800. J/kg-°C
To find the final temperature;
Heat capacity is given by the formula;
[tex] Q = mcdt[/tex]
Where;
Q represents the heat capacity or quantity of heat.
m represents the mass of an object.
c represents the specific heat capacity of water.
dt represents the change in temperature.
Making dt the subject of formula, we have;
[tex] dt = \frac {Q}{mc} [/tex]
Substituting into the equation, we have;
[tex] dt = \frac {90000}{4.5*1800} [/tex]
[tex] dt = \frac {90000}{8100} [/tex]
dt = 11.11°C
Now, to find the final temperature T2;
But, dt = T2 - T1
Substituting into the equation, we have;
T2 = 11.11 + 20
Final temperature, T2 = 31.11°C
The law of conservation of energy describes how the amount of energy can change in a closed system. Which of these statements correctly describes this law? A The amount of energy created when an object move is equal to the energy destroyed when it stops moving. B The amount of kinetic energy in a system is a constant value C Energy can be converted from one form into another, but it cannot be destroyed D An object can have potential energy or kinetic energy, but not both at the same time.
Answer:
b
Explanation:
The density of iron is 7.97 g/cm. Express it in Sl unit.
Answer:
[tex]d=7970\ kg/m^3[/tex]
Explanation:
Given that,
The density of iron is 7.97 g/cm³.
We need to find the density in SI unit. The SI unit of density is kg/m³.
We know that,
1 kg = 1000 g
1 m = 100 cm
So,
[tex]7.97\ g/cm^3=7.97 \times \dfrac{(\dfrac{1}{1000})\ kg}{(\dfrac{1}{100}^3)\ m^3}\\\\=7970\ kg/m^3[/tex]
So, the density of the iron is [tex]7970\ kg/m^3[/tex].
The air going into the tyre was warmed up by the pumping. What effect will this have on the motion of Gad molecules in the air in the tyre?
Answer:
they are constantly bouncing everywhere and creating preasure
Explanation:
The motion of gas molecules in the air in the tyre will speed up.
What is motion of molecules?Molecular motion is defined as the movement of molecules in a certain direction. The molecular motions are affected by heat and temperature. This is because the temperature is the measurement of the average kinetic energy of the molecules and represents the motion of molecules.
What is kinetic energy?The kinetic energy of an object is the energy which it possesses due to its motion. It gives the work needed to accelerate a body of a given mass from rest to its stated velocity. To calculate kinetic energy
[tex]K.E = \frac{1}{2} mv^{2}[/tex]
Kinetic energy depends on the velocity of the object which means that when the velocity of an object doubles, its kinetic energy quadruples.
Kinetic energy must always be either zero or a positive value.
Kinetic energy is not a vector.
The gas molecules inside the tyre exert pressure on the walls of the tyre as the molecules collide with the walls of the tyre.
When the air in the tyre becomes hotter, the pressure rises as more collisions.
The pressure in the tyre increases as there will be more frequent collisions with the tyre wall.
To learn more about Molecular motion here
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Which of the following statements is true with regard to elastic and inelastic collisions
14.Which of the following is TRUE of a body in equilibrium.
I. The sum of the forces in one direction is equal to the sum of the
forces in the opposite direction
II. The sum of the clockwise forces is equal to the sum of the
anticlockwise forces
III. The sum of the clockwise moments is equal to the sum of the anticlockwise moments
a) I only
b) II only
c) I and III only
d) I, II and III
Answer:
Explanation:
One
All three statements are saying exactly the same thing.
1. one direction forces = opposite direction forces. Note forces have direction. Always remember that forces have direction and you must always say what that direction is.
2. Two is saying the same thing as one. It is just that 2 is more specific about what the direction is. Clockwise is different from anti clockwise.
3. moments are forces and distances. Forces always have direction. Distances sometimes do not. At your level of study, I don't think it does. Later on, you will learn the word displacement which always has direction and that direction must be stated.
Answer D.
15 We are told to answer just 1 or 2 questions from the same student's posting. There are 4 here, so I'm going to give you just brief answers.
You should realize by now that a loaded bus has it's center of gravity raised. The answer is B
16 A is true.
Technically anything to do with turning is a torque.
D is also true.
C is better worded than B. I would pick B as the odd one out.
17
This is rotating so they must be on the same side of the pivot point. The moments add.
20*3 + 10*2 = 60 + 20 = 80 Newton Meters. Notice C has the right numbers associated with it, but the distance is divided into a Newton. Wrong answer.
In this series of questions, moments are defined as Force * Distance.
A person is running at 2 m/s and 20 s later is running at 22 m/s. What is
the acceleration of the runner?
Copper has the has a property of becoming a permanent magnet True False
Answer:
False
Explanation:
If you have a strong enough magnetic field all matter is magnetic. But copper is so weakly magnetic that we can't observe it without very, very large magnetic fields. So the short answer is "No, copper isn't magnetic." This can quickly be tested by trying to pick up a penny with a magnet.
BRAINLIST PLS!
HURYY PLEASE
The processes that transform inputs to outputs are what part of a system?
the components
the surroundings
the flow
the boundary
A train having speed of 85 km/h takes 5 hours to travel from Kerala to Karnataka. Calculate the distance between Kerala and Karnataka
Answer:
the distance between Kerala and Karnataka is 425 km.
Explanation:
Given;
speed of the train, u = 85 km/h
time taken for the train to travel from Kerala to Karnataka, t = 5 hours
The distance between Kerala and Karnataka is calculated as;
Distance = speed x time
Distance = 85 km/h x 5 h
Distance = 425 km
Therefore, the distance between Kerala and Karnataka is 425 km.
A dance form geared towards maximizing burning calories, created around the ___________ culture.
American
Italian
Brazillian
African
Answer:
Explanation:brazilian
A 3.9 kg crate is accelerated from 7.0 m/s to 9.5 m/s. What is the amount of work needed to accelerate the crate to the nearest tenth of a joule?
Newton's Second Law says that the force applied to an object is equal to the mass of the object times its acceleration. In other words, F=ma. Use a rearranged version, a=F/m in order to calculate the acceleration of a 5 kg skateboard when you give it a push of 20 N. PLEASE HELP FAST!!
Here the force is 20 N and mass is 5 kg
acc= Force/mass
acc=20/5= 4m/s²
In nature, what gets energy from nuclear fusion?
Answer:
Fusion powers the Sun and stars as hydrogen atoms fuse together to form helium, and matter is converted into energy.
Write whether true or false...
a The forces on a floating object are balanced.
b The forces on a rocket taking off are balanced.
c The forces on a leaf accelerating to the ground are unbalanced.
d All objects that accelerate have balanced forces acting on them
Corrected versions of false statements:
E
Answer:
a --> true, b --> false, c --> true, d -->false
Explanation:
a) since it stays floating the gravity force and the upqards push is the same
b) if it's balanced the rocket won't move from the ground, the force of the rocket, has to exceed the force of gravity
c) since it's going in a diretion the force of gravity is exceeding the force pushing it up
d) since that are speeding up at a rate, meaning growing, the force is unbalanced.
EXPLAIN CONSERVATION OF MOMEMTUM WITH THE HELP OF COLLISION OF TWO OBJECT.
i hate this question.
Conservation of momentum - is when the total momentum before and after collision is equal.
Here is the formula darling,
p = p
mv = mv
See the pic for example. HmpH
Subduction creates ocean trenches true or false!
WILL MARK BRAINLIEST!
A ball has 600 J of GPE when it is 6 m above the ground. What is its mass?
A. 8 kg
B. 100 kg
C. 80 kg
D. 10 kg
Answer: 10
Explanation: 600j = m*10*6
600j/60= m
M=10kg
What is the force that attracts metal to other metals called?
1.) magnetism
2.)gravity
3.)nuclear
4.) electricity
Answer:
1. Magnetism
BRAINLIST PLS!
Section 2.2
6.
If an object has an acceleration of 20 cm/sec?. what do you know
about how its speed changes over time?
Answer:
Speed changes at the rate of 24 m/s for each second over time.
Explanation:
We are told the object's acceleration is equal to 24 m/s²
Now we know that acceleration can also be defined as the rate of change of speed with time. Also speed has a unit known as m/s.
Thus, we can rephrase the acceleration in this question to mean;
Speed changes at the rate of 24 m/s for every second with time.
A ball rolls 14.4 m in 12 12 sec. what is the speed
Answer:
1.2 mph
Explanation:
14.4 ÷ 12 = 1.2
According to Newton’s second law of motion, what is equal to the acceleration of an object?
Answer:. The acceleration of the object is directly proportional to the force and inversely proportional to the mass.
Explanation:
According to Newton s Second Law of Motion, also known as the Law of Force and Acceleration, a force upon an object causes it to accelerate according to the formula net force = mass x acceleration.
the empirical formula of (NaSO)
Answer:
NaSO
Explanation:
Since there is no common factor besides 1, the formula is already the empirical formula for this compound.
good luck, i hope this helps :)
A car accelerates on a road at 4.2 m/s2 for 6.5 seconds. How far does the car go doing this?
Answer:
mmmmmmmmmmm
Explanation:
mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
Sorry if it’s a bit blurry. But thanks for answering if you do!
Work done against gravity is equal to change in
O kinetic energy
O potential energy
O frictional energy
Answer:
potential
Explanation:
A plumber uses a spanner on a tap. She puts a force of 200N on the spanner 30cm from the tap. What is the size of the moment?
Answer:
60Nm
Explanation:
Given data
Applied force= 200N
length of spanner= 30cm to meter
= 30/100= 0.3m
We know that the formula for the moment is
P=Fl
that is
P= force * length
P= 200*0.3
P= 60Nm
Hence the moment is 60Nm
What are the 2 types of ions.
Answer:
Anions have more electrons than protons and so have a net negative charge. Cations have more protons than electrons and so have a net positive charge. Zwitterions are neutral and have both positive and negative charges at different locations throughout the molecule.
Explanation:
two students stand 4.0 meters apart and shake a jump rope, creating a standing wave with 5 antidotes. what is the wavelength of the standing wave?
1.6m
0.8m
4.0m
5.0m
Answer:
i think it is 5.0 m but im not sure sorry if im wrong
im in 7th grade
Explanation:
What is the momentum of a 1, 500 kg car traveling at 3m/s?
67,500 kgm/s
67.5 kgm/s
4.5 kgm/s
4,500 kgm/s
========================================
Work Shown:
To find the momentum, we multiply the mass and the velocity.
m = mass = 1500 kg
v = velocity = 3 m/s
p = momentum
p = m*v
p = (1500 kg)*(3 m/s)
p = (1500*3) kg m/s
p = 4500 kg m/s
The momentum of an object is the product of its mass and velocity. Thus momentum of the car with 1500 kg and velocity of 3 m/s is 4500 kg m/s.
What is momentum?Momentum is a physical quantity that measure the ability to keep the force which make an object moves faster. Momentum like force is a vector quantity and is characterized with magnitude and direction.
Momentum is the product of velocity and its mass. Hence as the mass or velocity increases, momentum also increases. Increase in momentum makes the object moves faster.
Given mass of car = 1500 Kg
velocity = 3 m/s
momentum = velocity × mass
= 1500 Kg × 3 m/s
= 4500 Kg m/s.
Therefore, the momentum of the car is 4500 kg m/s.
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2. What type of signals does the nervous system send? What carries these signals
Answer:
Nervous system messages travel through neurons as electrical signals. When these signals reach the end of a neuron, they stimulate the release of chemicals called neurotransmitters. Neurotransmitters travel across synapses, spaces between neurons or between neurons and other body tissues and cells.
Explanation: