Physics

A parallel-plate capacitor in air has a plate separation of 1.25 cm and a plate area of 25.0 cm2. The plates are charged to a potential difference of 244 V and disconnected from the source. The capacitor is then immersed in distilled water. Assume that distilled water is an insulator.(a) What is the charge on the plates before immersion?What is the charge on the plates after immersion?(b) What is the capacitance after immersion?What is the potential difference after immersion?(c) What is the change in energy of the capacitor??U = Uwater - Uair = 5 nJ
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Looking at the image below (a roller coaster model), explain why the potential energy went from 100 (at top) to zero, and the kinetic energy from zero to 100 (joules)?
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A sphere of mass m" = 2 kg travels with a velocity of magnitude ") = 8 m/s toward a sphere of mass m- = 3 kg initially at rest, as shown in the figure. The collision of the two spheres is elastic and the length of the rope is l = 4 m. a) Apply the conservation of the momentum for the system of the two spheres and calculate the speed of the sphere m- just after the collision. b) Calculate the maximum height of the mass m-. c) What is the value of the angle at the maximum height of the mass m-? d) If the sphere m- is instantaneously at rest at its maximum height, calculate the tension in the string. e) When the height of the sphere of mass m- from its lowest position is 1 m, calculate its speed. f) What is the tension in the string when the sphere of mass m2 is 1 m above its lowest position?
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A simple elevator ride can teach you quite a bit about the normal force as this rider below can (hopefully) tell you. There are three different scenarios given, detailing the rider\'s experience in an unnamed hotel. For each scenario, calculate the normal force, FN,1-3, acting on the rider if his mass is m = 76.6 kg and the acceleration due to gravity g = 9.81 m/s2. In scenario 1, the elevator has constant velocity. In scenario 2 the elevator is moving with upward acceleration a2 = 4.84 m/s2. Finally, in scenario 3, unfortunately for the rider, the cable breaks and the elevator accelerates downward at a3 = 9.81 m/s2.FN1= ___________ FN2= ___________ FN3= ___________-
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a third resistor is added in parallel with the first two.(picture shows 2 resistors connected in parallel to battery)What happens to the current in the battery?A. remains the sameB. increasesC. decreasesWhat happens to the terminal voltage of the battery?A. remains the sameB. increasesC. decreases
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Two blocks, 1 and 2, are connected by a rope R1 of negligible mass. A second rope R2, also of negligible mass, is tied to block 2. A force is applied to R2 and the blocks accelerate forward. Is the magnitude of the force exerted by the rope R1 on block 1 larger, smaller, or equal to the magnitude of the force exerted by R2 on block 2?
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A series of parallel linear water wave fronts are traveling directly toward the shore at 15.5 cm/s on an otherwise placid lake. A long concrete barrier that runs parallel to the shore at a distance of 3.10 m away has a hole in it. You count the wave crests and observe that 75.0 of them pass by each minute, and you also observe that no waves reach the shore at 62.3cm from the point directly opposite the hole, but waves do reach the shore everywhere within this distance.A) How wide is the hole in the barrier?B) At what other angles do you find no waves hitting the shore?
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Here on Earth you hang a mass from a vertical spring and start it oscillating with amplitude 1.9 cm. You observe that it takes 3.0 s to make one round trip. You construct another vertical oscillator with a mass 6 times as heavy and a spring 10 times as stiff. You take it to a planet where gplanet = 8.8 N/kg. You start it oscillating with amplitude 4.8 cm. How long does it take for the mass to make one round trip?
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An airplane is flying with a velocity of v0 at an angle of above the horizontal. When the plane is a distance h directly above a dog that is standing on level ground, a suitcase drops out of the luggage compartment.Part AHow far from the dog will the suitcase land? You can ignore air resistance.Take the free fall acceleration to be g.
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At standard temperature and pressure (0 CC and 1.00 atmatm ), 1.00 molmol of an ideal gas occupies a volume of 22.4 LL. What volume would the same amount of gas occupy at the same pressure and 25 CC ?
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Technician A says a change in circuit resistance will change the amount of current in the circuit. Technician B says a change in circuit voltage will change the amount of current in the circuit. Who is right?
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Suppose a light source is emitting red light at a wavelength of 700 nm and another light source is emitting ultraviolet light at a wavelength of 350 nm. Each photon of the ultraviolet light has:________. a) half the energy of each photon of the red light. b) twice the energy of each photon of the red light. c) four times the energy of each photon of the red light. d) either more or less energy than each photon of the red light, depending on the intensities of the two light sources.
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Heat is a) the amount of thermal energy in an object. b) the energy that moves from a hotter object to a colder object c) a fluid-like substance that flows from a hotter object to a colder object. d) both A and B. e) both B and C.
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A helium-filled weather balloon has a 0.90 m radius at liftoff where air pressure is 1.0 atm and the temperature is 298 K. When airborne, the temperature is 210 K, and its radius expands to 3.0 m. What is the pressure at the airborne location
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An explorer is caught in a whiteout (in which the snowfall is so thick that the ground cannot be distinguished from the sky) while returning to base camp. He was supposed to travel due north for 5.3 km, but when the snow clears, he discovers that he actually traveled 8.4 km at 47o north of due east. (a) How far and (b) in what direction (south of due west) must he now travel to reach base camp
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The greenhouse effect plays a major role in the climate of a planet. Visit the Greenhouse Effect AstroTour (Links to an external site.), and use what you learn there to choose all the statements below that are correct. Note that 273 K = 0C = 32F.
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A rock is thrown with a velocity v0, at an angle of 0 from the horizontal, from the roof of a building of height h. Ignore air resistance. Calculate the speed of the rock just before it strikes the ground, and show that this speed is independent of 0.
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Betty weighs 400 N and she is sitting on a playground swing seat that hangs 0.21 m above the ground. Tom pulls the swing back and releases it when the seat is 1.09 m above the ground. The acceleration of gravity is 9.8 m/s 2 . How fast is Betty moving when the swing passes through its lowest position? Answer in units of m/s.
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A cylindrical shell of radius 7.1 cm and length 251 cm has its charge density uniformly distributed on its surface. The electric field intensity at a point 25.2 cm radially outward from its axis (measured from the midpoint of the shell ) is 37400 N/C.(a) What is the net charge on the shell? (b) What is the electric field at a point 4.07 cm from the axis? The value of Coulombs constant is 8.99 10^9 N m^2/C^2.
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While surveying a cave, a spelunker follows a passage 190 m straight west, then 220 m in a direction 45.0 east of south, and then 270 m at 30.0 east of north. After a fourth unmeasured displacement, she finds herself back where she started. Use vector components to find the magnitude and direction of the fourth displacement.
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A ball is dropped and bounces off the floor. Its speed is the same immediately before and immediately after the collision. Which of the following is true about the collision between the ball and the floor?a) The ball's momentum is conserved.b) The ball's momentum changes direction but not magnitude.c) The ball's momentum changes magnitude but not direction.d) The impulse delivered to the ball by the floor is zero.e) The impulse delivered to the floor by the ball is zero.
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Work is the product of ____ and an object's displacement.
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The olive oil in a bottle has a mass of 360 g. If the density of olive oil is 0.9 g/mL, what is its volume?A.300 mLB.400 mLC.500 mLD.600 mL
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In this section of a circuit, resistors R1, R2, and R3 combine for an equivalent resistance of 4.0 ohm. What is R2? Let R1 = 6.0 ohm and R3= 2.0 ohm.
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