An elevator packed with people has a mass of 1900 kg.
The elevator accelerates upward (in the positive direction) from rest at a rate of 1.95 m/s2 for 2.4 s. Calculate the tension in the cable supporting the elevator in newtons.
The elevator continues upward at constant velocity for 8.1 s. What is the tension in the cable, in Newtons, during this time?
The elevator experiences a negative acceleration at a rate of 0.75 m/s2 for 2.8 s. What is the tension in the cable, in Newtons, during this period of negative accleration?
How far, in meters, has the elevator moved above its original starting point?
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Hot & Cold compress
1. What are compresses?
2. What conditions would benefit from hot compresses?
3. What conditions would benefit from cold compresses?
4. How do you create a compress?
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The 1500-kg truck reaches a speed of 50 km/h from rest in a distance of 60 m up the 10% incline with constant acceleration. Calculate the normal force under each pair of wheels and the effective coefficient of friction between the tires and the road during this motion.
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Explain the relationship between Maxwell’s differential and integral formulations clearly and neatly. I am asking for an explanation, not derivation. Will give thumbs up. Again please write legibly. Thank you
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Temperatures of gases inside the combustion chamber of a four‑stroke automobile engine can reach up to 1000 ∘C.1000 ∘C. To remove this enormous amount of heat, the engine utilizes a closed liquid‑cooled system that relies on conduction to transfer heat from the engine block into the liquid and then into the atmosphere by flowing coolant around the outside surface of each cylinder.
Suppose that, in a particular 55‑cylinder engine, each cylinder has a diameter of 8.50 cm,8.50 cm, a height of 10.4 cm,10.4 cm, and a thickness of 3.78 mm.3.78 mm. The temperature on the inside of the cylinders is 195.2 ∘C,195.2 ∘C, and the temperature outside, where the coolant passes, is 134.2 ∘C.134.2 ∘C. The temperature of the incoming liquid (a mixture of water and antifreeze) is maintained at 101.3 ∘C.101.3 ∘C.
What volume flow rate of coolant ??Vt would be required to cool this engine? Assume that the coolant reaches thermal equilibrium with the outer cylinder walls before exiting the engine. The specific heat of the coolant is 3.75 J/g⋅∘C3.75 J/g⋅∘C and its density is 1.070×103 kg/m3.1.070×103 kg/m3. The cylinder walls have thermal conductivity of 1.10×102 W/m⋅∘C.1.10×102 W/m⋅∘C. Assume that no heat passes through the ends of the cylinders.
??=Vt=
cm3s
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Would the speed of sound in a monatomic gas like helium be the same as it would be in air (primarily a diatomic gas)? Why? Assume that both gases have the same density and exist at the same pressure.
Yes. If the pressure and density of both gases are the same, then the speed of sound must be the same.
No. The energy that goes into molecular bonds in the diatomic gas makes the effective spring constant of the gas different from that of the monatomic gas.
No. It is impossible for both gases to have the same density, so the speed of sound cannot possibly be the same in different gases.
Yes. The oscillating medium in each case can be approximated to be the same.
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A novelty collision device known as the executive toy consists of five identical metal balls. When one ball swings in, after multiple collisions, one ball swings out at the other end of the row of balls. When two balls swing in, two swing out; when three swing in, three swing out, and so on-always the same number out as in. Suppose that one ball, with mass m, swing in and collide with the next ball with a velocity v. Why don’t two ball swing out at the other end with a velocity of v/2? Clearly establish the reasoning and physical principles to receive full credit.
Can someone explain to me what laws are being used here and how it relates to the question? Thank you.
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What's the Fourier transform of the following equations:
1) f(t)=1/(t^2+a^2) a is a constant
2) e^[-absolute value(t)/a]*cos(b*t) a and b are constants
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Coulomb's Law
1. What evidence do you see that Newton's third law applies to electrostatic forces?
2. Electric force is a force of attraction or repulsion between objects based on their charges and their distance apart.
(a) When is the electric force attractive?
(b) When is the electric force repulsive?
3. Explain how electric forces are like gravitation forces and how they differ.
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1: A car, A, is stationary with the engine running. A second car, car B, passes car A at a constant speed of 12 m/s. at this moment car A accelerates at 0.5 m/s2.
A: Sketch the two events on the time vs position graph.
B: How far down the road does car A catch car B.
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A chandelier with mass mmm is attached to the ceiling of a large concert hall by two cables. Because the ceiling is covered with intricate architectural decorations (not indicated in the figure, which uses a humbler depiction), the workers who hung the chandelier couldn't attach the cables to the ceiling directly above the chandelier. Instead, they attached the cables to the ceiling near the walls. Cable 1 has tension T1T1T_1 and makes an angle of θ1θ1theta_1 with the ceiling. Cable 2 has tension T2T2T_2 and makes an angle of θ2θ2theta_2 with the ceiling.
Find an expression for T1T1T_1, the tension in cable 1, that does not depend on T2T2T_2.
I have been trying to answer this one question and can't seem to get a correct order if someone can please help me.
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Imagine that you are in a rowboat with a crate of fruit. You are having a lovely time with our crate, but when you row the boat to the middle of the pond, you decide to drop the crate off the boat (without capsizing the rowboat) and watch it sink to the bottom of the pond. Assuming the depth of water in the pond could be measured, explain in detail (using mathematical and diagrammatical support) the relationship between the depth of the water when the crate was in the rowboat and the depth of the water after the crate has sunk to the bottom of the pond. Note: mathematical does not imply the use of numbers.
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7. A cue ball traveling horizontally at 2.5 m/s strikes a stationary 8-ball, causing the 8-ball to travel at a 30◦ angle with respect to the horizontal. If the two have the same mass, (a) What are the speeds of the cue and 8-ball post-collision? (b) Using your results, indicate what kind of collision occurred. You must back up your conclusion using your results.
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Two methods are used to generate 1 GWhe of electricity: (1) burning coal with a generation efficiency of 30% and (2) burning MSW with an efficiency of 25%. (The energy content of coal is 31 MJ/kg.) For MSW generation, assume an energy content of 10 MJ/kg and a total net energy requirement of 5000 MJ/tonne for collection and transportation, which is provided by burning fossil fuels at 20% efficiency. The MSW consists of 50% carbon-neutral organic material and 50% fossil fuel–derived material. (The energy content and the density of petroleum is 35 MJ/kg and 0.72 kg/L, respectively.) Compare the relative contributions to greenhouse gas emissions for these two methods. Ignore any effects of possible carbon sequestration.
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Calculate the enthalpy of fusion (KJ/mole) for ice using the
following lab data:
(HINT: Think about the heating curves for H20)
Mass of empty calorimeter + stir bar: 255.060 g
Mass of calorimeter, stir bar, and warm water: 309.602 g
Mass of calorimeter, stir bar, water, and melted ice:
312.170g
Mass of warm water in calorimeter: 54.543 g
Mass of ice added: 2.568 g
The initial temperature of water: 35.3 C
The final temperature of water/melted ice: 31.1 C
Specific heat of water: 4.184 J
Hfusion of water: -285
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