Answer:
7.894 MJ
Explanation:
Given that:
The mass of the saturated water vapor = 3.7 kg
The pressure of the saturated water vapor = 0.4 MPa
From saturated properties of steam tables when the pressure is at 0.4 Mpa
The enthalpy in (kJ/kg);
hf = 604.7 kJ/kg
hg = 2738.1 kJ/kg
The rejected heat during this process is:
Q = m(hg - hf)
Q = 3.7(2738.1 - 604.7) kJ/kg
Q = 3.7(2133.4) kJ/kg
Q = 7893.58 kJ/kg
Q = 7.894 MJ
; (b) A uniform beam 150cm long weighs 3.5kg and
supported on knife-edges at its ends. The beam
supports a weight 7kg at a distance 30cm from
one end. Find the reactions of the supports.
Explanation:
(b) A uniform beam 150cm long weighs 3.5kg and
supported on knife-edges at its ends. The beam
supports a weight 7kg at a distance 30cm from
one end. Find the reactions of the supports.
1.
"An estimate of the future value of some variable" is the definition of
A. procurement
B. logistics.
C. a forecast.
D. capacity
Which of the following is a vector quantity? i. Force ii. Velocity iii. Acceleration iv. All of these 5771
Option ( iv ) is the correct answer.
☛ DefinitionA vector quantity the physical quantity that has both direction as well as magnitude.
Describe the laws of liquid pressure and explain the term fluid. (Please try to give the correct answer 'coz it's urgent!)
Answer:
The laws of liquid pressure are: ... The liquid pressure at a point inside the liquid is same in all directions. The liquid pressure at a point inside the liquid is directly proportional to the depth of that point from the free surface of liquid. The pressure of liquid at same depth is different for different liquids
Answer:
The laws of liquid pressure:
The pressure that is inside the liquid rises with the intensity from the surface of a liquid.
The term fluid:
Fluid is basically liquid and a substance that is known to have no certain shape. The opposite of the term fluid would be solid.
A low-power laser used in a physics lab might have a power of 0.50 mW and a beam diameter of 3.0 mm. Calculate:a.The average light intensity of the laser beam.b. The intensity of a lightbulb producing 100-W light viewed from 2.0 m.c.Compare the intensity of the laser to the intensity of the lightbulb. Is it advisable to look directly at a laser
Answer:
A) I_laser = 70.74 W/m²
B) I_bulb = 1.989 W/m²
C) it is not advisable to look at the laser beam directly.
Explanation:
We are given;
Power; P = 0.50 mW = 0.5 × 10^(-3) W
Diameter; d = 3 mm = 0.003 m
Radius; r = d/2 = 0.003/2 = 0.0015 m
A) Area of beam; A = πr²
A = 0.0015²π
Now, formula for average intensity is;
I = P/A
I = (0.5 × 10^(-3))/0.0015²π
I = 70.74 W/m²
B) We are told to find the intensity of a lightbulb producing 100-W.
Thus, P = 100 W
A light bulb is spherical in shape. Thus;
Area; A = 4πr²
We are told it's 2 m away.
Thus; r = 2 m
A = 4π(2)²
A = 16π
Thus, I = P/A = 100/16π
I = 1.989 W/m²
C) The intensity of the laser beam is far greater than that of the light bulb. Thus, it is not advisable to look at the laser beam directly.
A 6 kg object's Ug increases by 150 J. What was its change in height?
Please help I don’t understand this and fast please
Answer:
2.5 m
Explanation:
Potential energy is the energy stored in an object as a result of its position relative to other objects
The change in potential energy is given by:
ΔPE = mgh;
where ΔPE is the change in potential energy, m is the mass if the object, g is the acceleration due to gravity and h is the change in height of the object.
Hence given that g = 10 m/s², ΔPE = 150 J, m = 6 kg, hence:
ΔPE = mgh
150 = 6 * 10 * h
150 = 60h
h = 2.5 m
Hence the change in height is 2.5 m
state the term used to describe the turning force exerted by the man pushing down on a lever to lift one end of a heavy log
The term used to describe the turning force exerted when pushing an object is effort.
What is effort?The is the input force or force applied at one point of a lever in order to overcome a load.
The relationship between effort, load and mechanical advantage of a lever is given as;
M.A = L/E
where;
M.A is mechanical advantageL is the loadE is the applied force or effortThus, the term used to describe the turning force exerted when pushing an object is effort.
Learn more about effort here: https://brainly.com/question/24237657
If the final velocity is 0. third equation of motion will be
Answer:
vf²=vi²+2a∆x
Explanation:
The third equation of motion gives the final velocity of an object under uniform acceleration given the distance traveled and an initial velocity: v 2 = v 0 2 + 2 a d . v^2=v_0^2+2ad. v2=v02+2ad. The graph of the motion of the object.
Plutonium-32 has a half-life of 14.2 days. After 99.4 days, how much of what was originally a 499.2 gram sample remains?
14 grams
3.9 grams
35.7 grams
0.71 grams
Answer:
3.9 gm remains
Explanation:
499.2 ( 1/2)^(99.4/14.2) = 3.9 gm
Observe the given figure and find the the gravitational force between m1 and m2.
Answer:
The gravitational force between m₁ and m₂, is approximately 1.06789 × 10⁻⁶ N
Explanation:
The details of the given masses having gravitational attractive force between them are;
m₁ = 20 kg, r₁ = 10 cm = 0.1 m, m₂ = 50 kg, and r₂ = 15 cm = 0.15 m
The gravitational force between m₁ and m₂ is given by Newton's Law of gravitation as follows;
[tex]F =G \cdot \dfrac{m_{1} \cdot m_{2}}{r^{2}}[/tex]
Where;
F = The gravitational force between m₁ and m₂
G = The universal gravitational constant = 6.67430 × 10⁻¹¹ N·m²/kg²
r₂ = 0.1 m + 0.15 m = 0.25 m
Therefore, we have;
[tex]F = 6.67430 \times 10^{-11} \ N \cdot m^2/kg \times \dfrac{20 \ kg\times 50 \ kg}{(0.1 \ m+ 0.15 \ m)^{2}} \approx 1.06789 \times 10^{-6} \ N[/tex]
The gravitational force between m₁ and m₂, F ≈ 1.06789 × 10⁻⁶ N
Use the equation d=st where d= distance, s= speed, and t= time. If you ride a skateboard at a speed of 8m/s for 12 seconds, how far do you travel
Answer:
96 meters
Explanation:
d = st
d = (8 m/s)(12 s)
d = 96 m
PLS PLS PLS HELP ME! IT IS DUE IN TEN MINUTES
For his next stunt, Super Dave (80 kg) starts running at 2.00 m/s, then slides down a frictionless slide which is elevated 12.0 m above the ground, then slides across the rough asphalt ground to slow him to a stop (ouch!) He slides across the asphalt for 8.00 m before coming to a stop. What is the coefficient of friction between Super Dave and the ground?
Answer:
Preface to Students: Welcome to Physics! iv. 1 Motion. 1. 1-1 Speed, Velocity, and. Acceleration. 1. 1-2 Free Fall. 8. 2 Vectors and Projectiles.
257 pages·3 MB
Explanation: I hope this helpssss!!!
Water falls down as a stream from a tap. Why does it not scatter?
Answer:
as it hits the ground it's dispersed and this causes it to move in different directions
A magnet falls through a loop of wire with the south pole entering first. After it has fallen all the way through the wire loop so that the north pole end is moving away from the loop, what is the direction of the induced current in the loop (as viewed from above, looking down on the magnet)
Answer:
The induced current direction as viewed is clockwise
Explanation:
Lenz's Law states that the induced e. m. f. causes current to be driven in the loop of wire in such a way as to generate magnetic field that are oppose the magnetic flux change which is the source of the induced current
Therefore, as the magnet approaches the coil with the south pole, the coil produces current equivalent to the upward movement of the south pole of a permanent magnet through it which according to Flemings Right Hand Rule is clockwise
Therefore;
The direction of the induced current in the loop (as viewed from above, looking down the magnet) is clockwise
Please help! Will mark Brainliest.
Answer:
18 Nm
Explanation:
if the correct answer
28 Why is soft iron used for the core of an electromagnet?
А Soft iron easily becomes a permanent magnet.
B Soft iron is a good electrical conductor.
с Soft iron is a poor thermal conductor.
D Soft iron loses its magnetism when the current in the coil is switched off.
Answer:
An electromagnet is a form of magnet that is made by the passage of electric current through a coil of wire. The core of an electromagnet increases the strength of the produced magnetic field
Soft iron is used as the core of an electromagnet because soft iron is a magnetic material and therefore it is permeable to and becomes magnetized by the magnetic field coming from the flowing current, thereby allowing more flux to pass through the core of the electromagnet, producing a magnetic field strength that is several times that of an air core electromagnet as the relative permeability (to magnetic flux, compared to vacuum) of soft iron is about 64 × 10³
However, once the current is switched, the soft iron does not remain its magnetic, and therefore, the electromagnet becomes demagnetized, thereby being able to maintain its electromagnetic characteristics (being made magnetic by the flow of electric current)
Explanation:
The refractive index of water is 1.33
and that of diamond is 2.42. Draw a labelled diagram to show how a light ray bends when it travels from water
into diamond.
Explanation:
light travel slower in daimond
if you rub a ballon with wool or duster it can charge it negatively where do these extre charge come from?
Answer:
The electrons come from the free electrons in wool which contains moisture or other forms of additives that creates impurity centers which causes the wool to be electrically conductive
Explanation:
Wool which is mixed with certain substances, conducts electricity in a manner similar to the wool-water system that give rise to centers of impurities where electrical conduction takes place
The ability to conduct electricity is related to the presence of free electrons on a material. Therefore, when a balloon, which is an insulator, is rubbed with wool, some of the mobile electrons on wool, which is also an insulator without the presence of substances that aid its electrical conductivity, are transferred to the balloon, thereby making the balloon to be negatively charged
You are pulling a sled using a horizontal rèpe, as shown in the diagram. The rope pulls the sled. exerting a force of 50 N to the right. The snow exerts a friction force of 30 N on the sled to the left. The mass of the sled is 50 kg.
Find the sun of the force on the self
Determine the acceleration of the sled
If the sled has an initial velocity 2m/s to the right, how fast will it be traveling after 5 seconds?
Answer:
Part 1
20 N
Part 2
0.4 m/s²
Part 3
4 m/s
Explanation:
The force which pulls the sled right = 50 N
The friction force exterted towards left by the snow = -30 N
The mass of the sled = 50 kg
Part 1
The sum of the forces on the sled, F = 50 N + (-30) N = 20 N
Part 2
The acceleration of the sled is given as follows;
F = m·a
Where;
m = The mass of the sled
a = The accelertion
a = F/m
∴ a = (20 N)/(50 kg) = 0.4 m/s²
The acceleration of the sled, a = 0.4 m/s²
Part 3
The initial velocity of the sled, u = 2 m/s
The kinematic equation of motion to determine the speed of the sled is v = u + a·t
The speed, v, of the sled after t = 5 seconds is therefore;
v = 2 m/s + 0.4 m/s² × 5 s = 4 m/s.
A person slaps her leg with her hand, which results in her hand coming to rest in a time interval of 2.25 ms2.25 ms from an initial speed of 4.25 m/s4.25 m/s . What is the magnitude of the average contact force exerted on the leg, assuming the total mass of the hand and the forearm to be 1.75 kg1.75 kg
Answer:
The force is 3305.6 N.
Explanation:
Final velocity, v = 0
time, t = 2.25 ms
initial velocity, u = 4.25 m/s
mass, m = 1.75 kg
Let the acceleration is a.
Use first equation of motion.
v = u + a t
0 = 4.25 + a x 0.00225
a = - 1888.9 m/s^2
The force is
F = ma
F = 1.75 x 1888.9
F = 3305.6 N
Derive the following equations. :a=u-v by t
describe the forest ecosystem with examples
A forest ecosystem describes the community of plants, animals, microbes and all other organisms in interaction with the chemical and physical features of their environment: Specifically, a terrestrial environment dominated by trees growing in a closed canopy — a forest, in other words.
Hope this helps you buddy! :)
Define electric current and drift velocity.
Answer:
Explanation: The voltage or potential difference between two points is defined to be the change in ... I = qnAv relates the drift velocity to the current
What is concave mirror?
Answer:
A concave mirror, or converging mirror, has a reflecting surface that is recessed inward (away from the incident light). Concave mirrors reflect light inward to one focal point. They are used to focus light.
A solenoid passing by a current of 5.0 A generates a magnetic field at its diameter of 50 μT. Thus the number of spirals per length scale is:
A. 5.0 / π Spear / m
B. 10 / π Spear / m
C. 20 / π Spear / m
D. 25 / π Spear / m
Answer:
D. 25 / π Spiral / m
Explanation:
Given;
current, I = 5 A
magnetic field strength, B = 50 μT = 50 x 10⁻⁶ T
The magnetic field strength is given as;
[tex]B = \mu_0 nI\\\\where;\\\\\mu_0 \ is \ permeability \ of \ free \ space = 4\pi \times 10^{-7} T/A.m\\\\n \ is \ the \ number \ of \ spirals \ per \ length\\\\n = \frac{B}{\mu_0 I} = \frac{50 \times 10^{-6}}{5\times 4\pi \times 10^{-7}} = \frac{25}{\pi } \ spirals /m \\\\[/tex]
Therefore, the correct option is D. 25 / π Spiral / m
What is the purpose of the lab the importance of the topic and the question you are trying to answer?
perpose of lab is to store apparatus and do some experiment
Helps someone to know the exert lengh of something
A spring has a spring constant of 5 N/m and is stretched 10 m. What its U,?
a. 50 J
b. 70 J
c. 90 J
d. 250 J
Answer
I am not sure but it is may be 50J
I hope that's, this answer is fine.
A golf club hits a 0.04551 kg golf ball off a golf tee. The club is in contact with the ball for 0.020 s, and the force applied by the club is 115 N. What is the speed of the ball as it leaves the tee
Answer:
v = 50.5 m/s
Explanation:
F = (m)(^v/^t)
115N = (0.04551kg)(v/(0.020s))
2,526.917161 m/s² = v/(0.020s)
v = 50.53834322 m/s
v = 50.5 m/s
How long does it take a car travelling at 80 m/s to decelerate to 18 m/s with an acceleration rate of -16m/s?
We know
[tex]\boxed{\sf a=\dfrac{v-u}{t}}[/tex]
[tex]\\ \sf\longmapsto t=\dfrac{v-u}{a}[/tex]
[tex]\\ \sf\longmapsto t=\dfrac{18-80}{-16}[/tex]
[tex]\\ \sf\longmapsto t=\dfrac{-62}{16}[/tex]
[tex]\\ \sf\longmapsto t=3.8s[/tex]
4. diference between VR and efficiency
Answer:
Velocity ratio of simple machine is the ratio of distance travelled by effort to the distance travelled by load in the machine. The efficiency of a simple machine is defined as the ratio of useful work done by machine (output work) to the total work put into the machine (input work).
