Answer:
R=v2isin2Big R
=v I 2 sin 2 B I g
1. if the work done to move a box to a distance of 6 metres equals 120 joules. calculate the force
2. Calculate the potential energy of a book with a mass of 1.5 kg placed on top of a shelf with a height of 2 m.
(Knowing that the acceleration due to gravity = 10 m/s2
).
3. What is meant by?
The potential energy of an object = 20 joules.
Explanation:
1. W = F x D
F = W/D
F = 120/6 = 20Newton
2. P. E = mgh
P. E = 1.5x10x2 = 30Joules
3. It means that the energy the body possesses at that point is 20Joules
A fairly efficient steam turbine engine fired by coal is used to drive an electric generator. The generator operates between 2100°C and 385°C.
(a) Determine the maximum possible efficiency of the engine.
Answer: 72.3 %
Formula:
e = 1 - (Tc / Th) = 1 - (Qc / Qh) = ( W / Qh)
Explanation: Unsure??
(b) The engine absorbs 1.15 105 J from the hot reservoir every second. If the actual efficiency of the engine is 40.3%, determine the mechanical power the engine delivers.
Answer: 46 kW
Explanation:
Energy absorbed by the engine (J) * actual efficiency of the engine (%) = mechanical power the engine delivers (kW)
How does 1 - (385/2100) = 72.3 % ?
What do I Plug in to make e = 72.3 %
Use kelvin not celsius
C + 273 = K
This will fix my problem of the equation not making sense.
What is normal air pressure
Standard sea-level pressure, by definition, equals 760 mm (29.92 inches) of mercury, 14.70 pounds per square inch, 1,013.25 × 103 dynes per square centimetre, 1,013.25 millibars, one standard atmosphere, or 101.325 kilopascals.
Plzzzzzzzzz
Help
Will give brainlessness
Answer:
1. A
2. A; distance is scalar, displacement is vector
3. C ; position is on the y-axis
What can the magnetic fields influence?
A) It can cause objects to be pulled towards the magnet and pushed away from the magnet.
B) It only causes a repel force between the magnets.
C)It cause only an attraction force.
Explanation:
Magnetic fields are areas where an object exhibits a magnetic influence. The fields affect neighboring objects along things called magnetic field lines. A magnetic object can attract or push away another magnetic object. You also need to remember that magnetic forces are NOT related to gravity.
whats 1+0 n3rje'hefruhhhhhhhhhhhhhhhhhhhhhhhhtrrrrrrrrrrrrr
Answer:
1
Explanation:
cause 1+0=1
3.
If the specific heat of iron = 0.46 J/g Cº, how much heat is needed to warm 50 g of
iron from 20° C to 100° C?
Answer:
1.84 kJ (kilojoules)
Explanation:
A specific heat of 0.46 J/g Cº means that it takes 0.46 Joules of energy to raise the temperature of 1 gram of iron by 1 Cº.
If we want to heat 50 g of iron from 20° C to 100° C, we can make the following calculation:
Heat = (specific heat)*(mass)*(temp change)
Heat = (0.46 J/g Cº)*(50g)*(100° C - 20° C)
[Note how the units cancel to yield just Joules]
Heat = 1840 Joules, or 1.84 kJ
[Note that the number is positive: Energy is added to the system. If we used cold iron to cool 50g of 100° C water, the temperature change would be (Final - Initial) or (20° C - 100° C). The number is -1.84 kJ: the negative means heat was removed from the system (the iron).
Describe the changes that occur inside a helium balloon as it rises from sea level
Answer:
The balloon expands in the number of particles per cubic centimeter decreases. This happens because as it expands there is a decrease in the density of area. The Dead Sea is a solution that is so dense that you easily float on it.
A group of waves is propagated at a speed that is ________ the speed of the individual waves in deep water.
How many minutes did it take for all of the gold in the sample to change from solid to liquid? Time taken minutes =
Calculate the amount of time it takes to heat the water by dividing the power used to heat the water, which was determined to be 1.867 with the heater element rating, listed in kW. So if your heater element rating was 3.6 kW, your equation would look like this: heating time = 1.867 ÷ 3.6, or heating time =0.52 hours.
A piece of iron has a density of 7.86 g/cm3 and a mass of 1.09 x 10^-1 kg. Calculate the volume of the piece of iron.
Name any three things that cause soil pollution
Answer:
garbage , polluted water dam, unexpected dust particle
A potted plant falls from the window of an apartment building. It falls for 2.0
s and then hits the ground. What is the speed of the plant just before it hits
the ground? Assume only gravity is acting on it.
A)20 m/s
B) 9.8 m/s
C) 2.0 m/s
D) 4.9 m/s
Answer:
D) 4.9 m/s
Explanation:
Speed of Object in Free Fall
s = Rate of Acceleration, Due to Gravity × Length of Time
s = 9.8 × 2.0
s = m/s (Round Up to The Nearest Whole Number)
--
m/s = 9.8 ÷ 2.0 = 4.9 m/s
Which statement or phrase best describes the currently accepted model of the atom?
1. Atoms are extremely small spheres which cannot be divided into smaller particles.
2. Atoms are like plum pudding with most of the mass being positively charged and evenly spread throughout the atom and electrons randomly placed throughout this mass.
3. Atoms contain a very small, dense, positively charged nucleus with electrons circling the nucleus
in defined paths called orbits.
4. Atoms contain a very small, dense, positively charged nucleus with electrons moving around the
nucleus in the electron cloud.
Answer:
4
Explanation:
Answer:
i am pretty sure that it is 4
How much energy must be transferred out of the system as heat q to lower its temperature to 0∘c?.
Answer:
2.20 × 104 J
Explanation:
How much energy must be transferred out of the system as heat Q to lower its temperature to 0?C? ANSWER Q = 2.20 x 10^4. Cooling Power of P is 36.6 W.
why the speed of sound in solid and liquid is not signoficantly affected by temperature
Explanation:
because the molecules are closer together and more tightly bonded in solids
Find the volume of this figure.
4 dm
2 dm
3 dm
Answer:
4×2×3= 24dm^3
.......................
easy one - giving brainly if correct.
Gas.
HOPE YOU GET 100!
An object is in equilibrium. Which force vector diagram could represent the force(s) acting on the object
Answer:
velocity and force
Explanation:
Velocity and force vector diagram represent the force acting on the object.
What is vector diagram?Diagrams are called vector diagrams to use a vector arrowhead to show the magnitude or direction of a vector quantity. The velocity of an item in motion could be represented in vector diagrams. A vector diagram might be used, for instance, to depict the motion of an automobile traveling down a road.
What is force?A force was an influence that will have the power to alter an object's motion.
Therefore, velocity and force vector diagram represent the force acting on the object.
To know more about vector and force.
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A football player kicks the ball with an initial velocity of 28.3 m/s at an angle of 60° above the horizontal. The ball is in the air for a total of 5.00 s before hitting the ground. Ignoring air resistance, what would be the ball's horizontal displacement?
Hi there!
Since the ball is directed 60° above the horizontal, we must use its HORIZONTAL component to find its displacement.
We can take the cosine to do so:
vcosθ = 28.3cos(60) = 14.15 m/s
Since the ball is in the air for 5 sec, we can use the following equation:
displacement = velocity · time (d = vt)
Plug in the values:
d = 14.15 · 5 = 70.75 m
What is the horizontal acceleration of a ball that is launched horizontally with a velocity of 5. 6 m/s? â€""9. 8 m/s2 0 m/s2 5. 6 m/s2 9. 8 m/s2.
The horizontal acceleration of a ball that is launched horizontally is equal to: B. 0 [tex]m/s^2[/tex]
Given the following data:
Horizontal velocity = 5.6 m/sTo determine the horizontal acceleration of a ball that is launched horizontally:
Acceleration can be defined as the rate of change of velocity with respect to time. In Physics, the acceleration of an object or body is calculated by subtracting its initial velocity from the final velocity and dividing by the time.
Mathematically, acceleration is given by the formula;
[tex]Acceleration = \frac{V\; -\;U}{t}[/tex]
The projectile motion of an object launched horizontally has a constant velocity and as such its horizontal acceleration would be equal to zero meter per seconds square ([tex]0\;m/s^2[/tex]).
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A skydiver that has a weight of 1050 N. jumps from a plane at an altitude of 5000 m. How much work is performed on the skydiver?
Answer:
5.25MJ
Explanation:
Considering the weight of the skydiver constant over the descent -ie, the acceleration of gravity not decreasing as you go up the earth surfice, the work is simply the product of the two:
[tex]w= \vec F\cdot \vec x = Fx = 1050\times 5000 = 5,250,000 = 5.25MJ[/tex]
Some houses are built with very thick walls. Explain how these walls help to keep the houses
warm in the winter.
Thicker walls provide more materal for .......
to travel through from the inside to outside, so the
is less, keeping the houses warmer.
(2 marks)
Answer: It banks night-time cool to bring temperatures down in the day, and warms up over the course of the day and then releases the warmth at night. Thick walls or exposed solid floors can provide thermal mass. The shape of buildings matters too, and the orientation around each other so that the wind moves in particular ways. Hope this helps, tell me if I need to add anything. :))
which color of light, red or blue, travels faster in crown glass?
Answer:
Red
Explanation:
The index of refraction for red light in crown glass is smaller than the index of refraction for blue light, which means the speed of red light is larger than the speed of blue light in crown glass.
A very light rod 40cm long is pivoted at the centre. A weight of 50N is placed at one end. Where is the place to put a weight of 200N in order that the rod is in equilibrium?
Hi there!
We can go about this problem using a summation of torques.
In order to ensure the rod is in equilibrium, we must satisfy the condition:
Στ = 0
Since the rod is "very light", we can disregard its mass.
The equation for torque is:
τ = rFsinθ
In this instance, the torques are the weights of the objects and their distance from the pivot.
As the rod is 40 cm, the pivot is at 20 cm. Also, the torques must sum up to 0, so:
0 = rF1 - rF2
r1F1 = r2F2
0.20(50) = r2(200)
Solve:
10 = r2(200)
r2 = 0.05 m = 5 cm
The 200N weight must be put at a distance of 5 cm from the OTHER SIDE of the pivot in order to balance the rod.
Now explore friction force. Set the piece of plastic or wood on the table and push it steadily across the tabletop using your fingertip. Note how much opposition to your push you feel. Repeat the steps, but this time push the piece of plastic or wood across a rug, carpet, or piece of fabric. If you’re using fabric, be sure to secure the fabric so it doesn’t move. How does the opposition to the motion on the tabletop compare with that of the rug, carpet, or fabric? (I don't wanna do this so can someone answer this please)
Answer: If there is a higher friction, the opposition force is higher so that it can reduce our speed. So, a factor that affects friction is the roughness or smoothness of the surface of the object. In comparison of the table with the fabric, the fabric will have a more opposition force. As the surface of the fabric is usually rougher than the surface of a smooth table. As there is more friction on a fabric, we will feel more opposition force on our finger tip.
Hope it helped! :>
What electromagnetic wave is used in nuclear research and mineral exploration?.
The electromagnetic wave used in nuclear research and mineral exploration are gamma rays.
Electromagnetic waves refer to those rays that are found in the electromagnetic spectrum. They are collectively called light. Electromagnetic waves are used for different purposes.
Gamma rays are useful in nuclear research especially in identifying decaying radionuclides. Also, gamma rays are used for geologic mapping, mineral exploration, and identification of environmental contamination.
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the free body diagram shown above is for a 5 kg box on a rough surface being pulled to the right at a constant speed by a string that is at an angle of 30° above the horizontal. the coefficient of kinetic friction between the box and the surface is 0.30. the tension in this string is most nearly:
The tension in the string pulling the box is most nearly 17 N.
The given parameters;
mass of the box, m = 5 kginclination of the string, θ = 30°coefficient of kinetic friction, μ = 0.3The tension on the string is calculated by applying Newton's second law of motion as follows.
[tex]\Sigma F = ma[/tex]
at constant speed, acceleration, a, = 0
[tex]\Sigma F = 0\\\\T_x - \mu F_n = 0\\\\Tcos(\theta) - \mu F_n = 0\\\\Tcos(\theta)= \mu F_n\\\\T = \frac{\mu F_n}{cos(\theta)} \\\\T = \frac{0.3 \times 5 \times 9.8}{cos(30)} \\\\T = 16.97 \ N\\\\T \approx 17 \ N[/tex]
Thus, the tension in the string pulling the box is most nearly 17 N.
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How to calculate angular velocity.
Answer:
Answer below
Explanation:
We can rearrange this statement to get the angular velocity equation: = r v / |r|2, where all of these variables are vectors and |r| is the radius's absolute value. The angular velocity is really a pseudovector with a direction perpendicular to the plane of rotational movement.
The rotating movement of bodies is described by angular velocity. It determines how quickly they rotate around a central point. Rotations may be divided into two categories. The first explains the motion of an object's centre of mass around a certain point in space, which is referred to as an origin. Planets orbiting the Sun, for example, or an automobile exiting a roadway are two instances.
The first angular velocity equation is similar to the linear velocity equation: = (2 - 1) / t = / t, where 1 and 2 are two values of angles on a circle, and is the difference between them. t is the time it takes for the angle to shift. As you can see, there is a ratio of the positional change in a period for normal velocity, but we utilise angle instead of distance here. Definition of angular velocity using linear velocity The second angular velocity formula, v = r, may be obtained from the linear velocity and radius relationship using the cross product.
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(Hope this helps can I pls have brainlist (crown)☺️)
Select the correct answer.
What represents the value of the second-best alternative that a person gives up when making a choice?
OA. marginal spending
ОВ.
marginal benefit
OC. opportunity cost
OD. marginal cost
The answer should be opportunity cost