Objects with masses of 165 kg and a 465 kg are separated by 0.390 m. (a) Find the net gravitational force exerted by these objects on a 41.0 kg object placed midway between them. magnitude? direction? (b) At what position (other than infinitely remote ones) can the 41.0 kg object be placed so as to experience a net force of zero?

Which of the following electron jumps in a hydrogen atom emits the photon of highest frequency?

a) n=2 to n=3
b) n=1 to n=2
3) n=3 to n=2
4) n=2 to n=1

A 0.50-?F and a 1.4-?F capacitor (C1 and C2, respectively) are connected in series to a 15-V battery.

Part A. Calculate the potential difference across each capacitor. Express your answers using two significant figures separated by a comma.

Part B. Calculate the charge on each capasitor. Express your answers using two significant figures separated by a comma.

Part C. Calculate the potential difference across each capacitor assuming the two capacitors are in parallel. Express your answers using two significant figures separated by a comma.

Part D. Calculate the charge on each capasitor assuming the two capacitors are in parallel. Express your answers using two significant figures separated by a comma.

Polarized light is to have its polarization plane rotated by 90 degrees. In which of the following cases does the final beam have the greatest intensity?

Select one:

a. 1 polarizing filter, rotating the beam by 90 degrees

b. 3 polarizing filters, both rotate the beam by 30 degrees

c. 6 polarizing filters, each rotating the beam by 15 degrees

d. None of the above, polarized light can't be rotated

please explain the answer think it is C.

A flywheel with a diameter of 1.39 m is rotating at an angular speed of 194 rev/min. (a) What is the angular speed of the flywheel in radians per second? (b) What is the linear speed of a point on the rim of the flywheel? (c) What constant angular acceleration (in revolutions per minute-squared) will increase the wheel's angular speed to 1280 rev/min in 128 s? (d) How many revolutions does the wheel make during that 128 s?

5. a)Which component offers a measureable resistance to the circuit: Resistor or Capacitor?

b) Let's say you measure t_1/2 to be 0.3018 seconds and the resistance in the circuit is 68 Ohms. Then what is the capacitance in micro Farads?
answer in micro Farads.

c) t_1/2 means that the voltage (or charge) of the system will increase to half more of what is left in a time equal to t_1/2 seconds.
Therefore if a system is already at half charge (t_1/2 seconds after starting) then after t_1/2 more seconds the system will be charged to 50% plus half of 50%. That is 25% more, or 75% of the entire charge. Let's say that four t_1/2's have gone by. That means that the charge (or voltage) is at (50% + 1/2*50% + 1/2*1/2*50% + 1/2*1/2*1/2*50%) = 93.75% of maximum charge.
Yikes! Now look in your manual for a more simple mathematical derivation of this concept.

Given t_1/2 to be 0.9653 seconds, how long should it take to reach 75% of maximum charge?
answer in seconds.

2. On average, both arms and hands together account for 13% of a person's mass, while the head is 7.0%and the trunk and legs account for 80%. We can model a spinning skater with her arms outstretched as a vertical cylinder (head, trunk, and legs) with two solid uniform rods (arms and hands) extended horizontally.

Suppose a 68.0 kg skater is 1.50 m tall, has arms that are each 64.0 cm long (including the hands), and a trunk that can be modeled as being 32.0 cm in diameter. If the skater is initially spinning at 72.0 rpm with her arms outstretched, what will her angular velocity ?2 be (in rpm) after she pulls in her arms and they are at her sides parallel to her trunk? Assume that friction between the skater and the ice is negligble.

w2=

3. A child's top is held in place upright on a frictionless surface. The axle has a radius of ?=2.96 mm Two strings are wrapped around the axle, and the top is set spinning by applying ?=3.40 N of constant tension to each string. If it takes 0.440 s for the string to unwind, how much angular momentum does the top acquire? Assume that the strings do not slip as the tension is applied.

angular momentum:__________kg⋅m2s

Point P is located on the outer surface of the top, a distance ℎ=31.0 mm above the ground. The angle that the outer surface of the top makes with the rotation axis of the top is ?=27.0 . If the final tangential speed ?t of point P is 1.85 m/s , what is the top's moment of inertia?

moment of inertia: ______________kg⋅m2

It has been claimed that an insect called the froghopper (Philaenus spumarius) is the best jumper in the animal kingdom. This insect can accelerate at 4,000 m/s2 over a distance of 2.0 mm as it straightens its specially designed "jumping legs." Assuming a uniform acceleration, answer the following.

(a) What is the velocity of the insect after it has accelerated through this short distance? (Enter the magnitude of the velocity.) m/s

(b) How long did it take to reach that velocity? ms

(c) How high would the insect jump if air resistance could be ignored? Note that the actual height obtained is about 0.7 m, so air resistance is important here. m

A 50 kg uniform square sign, 2.00 m on a side, is hung from a 3.00 m rod of negligible mass. A cable is attached to the end of the rod and to a point on the wall 4.00 m above the point where the rod is fixed to the wall. What is the tension in the cable?

What is the horizontal component of the force exerted by the wall on the rod?

What is the vertical component of the force exerted by the wall on the rod?

Please answer part A

Three spaceships all broadcast a signal at the same frequency f₀. Spaceship #1 is at rest, spaceship #2 is traveling away from #1 at a speed v, and spaceship #3 is traveling away from #1 in a direction opposite that of #2 and also at a speed v. Determine the following in terms of f₀ when v = 0.40c.

(a) Frequency measured by #1 broadcast from #2

(b) Frequency measured by #1 broadcast from #3

(c) Frequency measured by #2 broadcast from #1

(d) Frequency measured by #2 broadcast from #3

(e) Frequency measured by #3 broadcast from #1

(f) Frequency measured by #3 broadcast from #2

1)A 861 g rubber ball is dropped from height 15.1 m, and it rebounds to height 3.15 m. Assuming there is no air friction, find the magnitude of the impulse, in N-s, exerted by the ground on the ball.

2)Milly (mass 98.7 kg) runs at 2.73 m/s along the positive x-axis and then jumps onto a stationary 278 kg box. Milly and the box slide across the floor for distance 0.357 m, and then they come to a stop. Find the coefficient of kinetic friction between the box and the floor.

3)Two astronauts float in deep space, at rest relative to each other. Including the equipment they carry, the first astronaut has total mass 521 kg and the second astronaut has total mass 615 kg. The first astronaut throws a 656 kg box of tools at 4.66, and the second astronaut catches the box. After the throw and catch: find the speed of one astronaut relative to the other, in m/s.

Please answer with a written response rather than calculations:

-describe conservation of momentum in elastic AND inelastic collisions

-describe the path of the center of mass for two colliding objects

-explain the relationship between conservation of energy in a collision and coefficient of restitution

-explain conversions between kinetic, gravitational potential, and magnetic potential energy

thanks

Consider a box with a lid 2.1 m wide and 0.62 m long. If the inside of the box is evacuated (i.e., its pressure is zero), how much force is required to open the lid?

The development of the internal-combustion engine caused fundamental changes in urban land-use patterns. The transformation from the core-dominated city to the modern suburbanized city took only about 50 years. Given the rapid pace of technological change, it seems likely that some future innovation will cause another transformation of cities. Given your knowledge of science fiction and fact, describe an innovation that would cause fundamental changes in the spatial structure of cities

Suppose you’re eating in yet another restaurant where the dishes are shared at the table and all placed uniformly on a rotating disk-like surface. Model this surface as a thin disk of radius 45.3 cm. Someone else has spun the surface, such that it is initially at an angular speed of 0.4 rev/s. The surface and food has a combined mass of 3.3 kg. The waiter, to show off, throws a new dish of dumplings (mass 0.8 kg) onto the surface at a speed of 0.5 m/s, such that the dish lands on and sticks to the very edge of the surface moving in the same direction as the rotating food. While this is happening, you quickly calculate the final angular speed of the food so that you can predict its location at any time before others have a chance to eat the dumplings. What is this speed, in rad/s?