Two point charges totaling 9.00 µC exert a repulsive force of 0.200 N on one another when separated by 0.712 m.

What is the charge on each if the force is attractive?

A student stands at the edge of a cliff and throws a stone horizontally over the edge with a speed of 10.0 m/s. the cliff is 50.0 m above a flat horizontal beach. (a) how long after being released does the stone strike the beach before the cliff? (b) find the speed just before the stone strikes the beach. (c) find the traveling horizontal distance for the stone

A 300 kg piano is being lowered into position by a crane while two people steady it with ropes pulling to the sides. Bob's rope pulls to the left, 11 ∘ below the horizontal, with 330 N of tension. Ellen's rope pulls toward the right, 28 ∘ below the horizontal.

Part A

What tension must Ellen maintain in her rope to keep the piano descending vertically at a constant speed?

Express your answer in newtons.

Part B

What is the tension in the vertical main cable supporting the piano?

Express your answer in newtons.

1) Which takes more work, slowing a car from 100km/h to 70km/h, or 70km/h to 0?

2) A 0.2kg falcon flies at 50m/s toward a 0.01kg shrew moving at 0.2m/s away from the falcon. What is the total kinetic energy of the falcon-shrew system?

5) Three capacitors, all initially without any dielectrics inserted, of C1 = 3 micro-farads, C2 = 7 micro-farads, and C3 = 15 micro-farads, are connected purely in series to a battery and the total stored energy of all three capacitors is 203 micro-joules. Then, the plates of C1 are brought closer by a factor of 2 and a dielectric with a dielectric constant of 1.7 is inserted into C2 while still connected in series to the same battery. (C3 does not change at all.) How much does the total stored energy of all three capacitors increase in micro-joules after the capacitors are changed? Not the factor change... how much does the stored energy go up in value.

what other elements does a star burn as fuel besides hydrogen?

A 2 kg ball is 60m in the air with the PE of 1176. It has a bouncing restitution coefficient of 0.50.

Calculate. What is the maximum speed of the ball before it hits the floor?

After hitting the floor, it bounces back up 15m in the air with a final PE of 294.

Calculate. What is the maximum speed of the ball after it hits the floor?

You have two fluids, water and a fluid that has a density that is 3/10 that of water. If a volume of water that has the same mass as

7.40 m³

of the other fluid fills a cubic aquarium, determine the pressure inside at the bottom of the aquarium. (Use 1000 kg/m³ for the density of water.)

___________ Pa

Two cars collide at an intersection. Car A, with a mass of 1900 kg , is going from west to east, while car B , of mass 1500 kg , is going from north to south at 12 m/s . As a result of this collision, the two cars become enmeshed and move as one afterwards. In your role as an expert witness, you inspect the scene and determine that, after the collision, the enmeshed cars moved at an angle of 65 ∘ south of east from the point of impact. Part A Part complete How fast were the enmeshed cars moving just after the collision? Express your answer using two significant figures. v = 5.8 m/s Previous Answers Correct Part B How fast was car A going just before the collision? Express your answer using two significant figures. How fast were the enmeshed cars moving just after the collision and how fast was car A going just before the collision?

a) Write down the state equation of an ideal gas. This equation can be utilized to derive any one of the macroscopic thermodynamic properties, p1, T1, or V1, of an ideal gas in state “1” when the other two properties and the gas’ conditions at some initial state “0” are known.

b) What is the ideal gas law? Express the law separately in terms of the amount of substance, the gas’ molar mass, the gas’ molar volume, and the gas’ number of particles (4 equations!).

c) When we divide the universal gas constant by Avogadro’s constant we obtain a new constant. What is this constant’s name? Derive its value and proper unit.

d) State Newton’s Law of Cooling and name all properties in the corresponding equation.

e) For most thermodynamic problems we use some standard definitions for pressure and temperature to which we relate our calculations. A popular choice is a standard air pressure of 1atm = 101325Pa at sea level and a temperature of T = 288.15K (or ϑ = 25°C), BUT there are many other standards in use! What is the barometric elevation equation which allows you to approximate the air pressure at an arbitrary height (idealized!)?

A spherical cannonball of mass 2M is launched with an initial velocity v0 at an angle of 45° above the horizontal. There is an explosive charge between the two halves of the cannonball which is detonated when the cannonball has reached the highest point of its trajectory. One half of the cannonball (mass M) is propelled backwards exactly along the original trajectory and lands back in the cannon (good trick!). Ignore air resistance for this problem.

a) Assuming level terrain, find the range of the center of mass of the system, i.e., how far away from the cannon does the center of mass of the system land?

b) Find the velocity of the second half of the cannonball (the one that doesn't land back in the cannon) immediately after the explosion.

c) How far away from the cannon does the second half of the cannonball land?

*Use Gauss's Law: Q1. Find the electric field (outside and inside) due to a uniformly charged solid sphere of radius “a” and the total charge Q.

Explanation with drawing will be appreciated.

1. Explain Bohr’s Theory of the Hydrogen Atom. When a hydrogen atom does absorbs or emits radiant energy? What kinds of spectrum is created when we observe the emission and absorption of radiant energy from a hydrogen atom? What significance these spectra have?

discuss the history of heron's fountain in 100-200 words

Review A 110 cm3 box contains helium at a pressure of 2.50 atm and a temperature of 120 ∘C. It is placed in thermal contact with a 180 cm3 box containing argon at a pressure of 3.60 atm and a temperature of 420 ∘C.  

What is the initial thermal energy of each gas? Correct answer: 41.8 J for He and 98.5 J for Ar

What is the final thermal energy of each gas?

How much heat energy is transferred, and in which direction?

What is the final temperature?

What is the final pressure in each box?