Point charges of 6.75 µC and

−4.00 µC

are placed 0.300 m apart. (Assume the negative charge is located to the right of the positive charge. Include the sign of the value in your answers.)

(a) Where can a third charge be placed so that the net force on it is zero?
m to the right of the

−4.00 µC

charge

(b) What if both charges are positive?
m to the right of the  4.00 µC charge

1. What is light? 2. What are the three models of light? 3. When is each model of light applicable? 4. What is visible light? 5. What is white light? 2-3 sentences each.

A person measures her heart rate by counting the number of beats in 30 s. If 42 ± 1 beats are counted in 30.0 ± 0.5 s, what is the heart rate and its uncertainty in beats per minute?

A 2100-m-high mountain is located on the equator.

How much faster does a climber on top of the mountain move than a surfer at a nearby beach? The earth's radius is 6400 km.

Express your answer to two significant figures and include the appropriate units.

When the police want to know how fast your car is going, they shoot a "radar gun" at the car. The radar gun emits waves at approximately 24.15 GHz. Those waves reflect off of your car and are detected by the same "radar gun" that emitted them. The detector can detect both frequency and intensity. Using concepts of general physics, explain how the radar gun works. You probably want to draw pictures, use an equation or two, and use words.

In uniform circular motion, which of the following quantities are constant?

Which of these quantities are zero throughout the motion?

a parallel-plate capacitor is oriented horizontally and charged so that there is an electric field of 50,000 V/m pointing up inside the gap of 1cm, which is filled with air. a.) With the charge on each plate remaining constant, the capacitor is immersed half-way in an oil of dielectric constant K=2.5 What is now the potential difference between the plates? b.) If on top of the oil, water (K=80) is poured to completely fill the upper part of the gap, what is now the potential difference between the plates? (since this measurement takes place over a short period of time, please treat water as an insulator, not as a conductor.)

Please do step by step clear and show eqations used. Thank you

A rocket designed to place satellites into orbit is carried to a cruising altitude. When the plane is flying in a straight line and at a constant speed of 850 km/h, the rocket is dropped. After the drop the plane continues to fly at the same pseed and in a straight line. The rocket falls for a bried time, and then its propulsion starts. Once the propulsion starts the combined effects of gravity and thrust give the rocket a non-constant acceleration of (29.43 + 0.44t) m/s^2 directed at an angle of 30.0 degrees above the horizontal. For safety the rocket should be at least 1.00km in front of the plane when it climbs through the plane's altitude. Ignore drag.

a) If the rocket falls for 5.15 s before engaging propulsion, how much total time will pass before the rocket passes back through the cruising altitude of the plane?
b) will the rocket safely pass 1.oo km in front of the plane for this free-fall time of 5.15s? What will be the horizontal distance between the rocket and the plane when they are at the same altitude ?

13.18 Two piano strings with the same mass and the same length are to be tuned to 440 Hz (A on the equal temperament scale). One string, with a tension of 300 N is already tuned to 440 Hz. The second string frequency is 435 Hz. a) Should the tension of string 2 be increased or decreased to tune the frequency to 440 Hz? b) How much must the tension of string 2 be changed to change the frequency from 435 Hz to 440 Hz?

14.2 The wavelength of a 450 Hz sound wave in air has a wavelength of 0.78 m. a) What is the speed of sound in air? b) What is the temperature?

I have done the first part of this problem, but I cannot figure out the second part. I know there are several different answers already posted on Chegg for this particular problem with different acceleration and time, but I need this one specifically, with a step by step solution. Again...just PART B....the answer to Part A is 201.72

A helicopter carrying Dr. Evil takes off with a constant upward acceleration of 4.20 m/s2. Secret agent Austin Powers jumps on just as the helicopter lifts off the ground. After the two men struggle for 8.20 s, Powers shuts off the engine and steps out of the helicopter. Assume that the helicopter is in free fall after its engine is shut off and ignore effects of air resistance. What is the maximum height above ground reached by the helicopter? y=201.72

Powers deploys a jet pack strapped on his back 5.40 s after leaving the helicopter, and then he has a constant downward acceleration with magnitude 1.90 m/s2. How far is Powers above the ground when the helicopter crashes into the ground?

Use principles of physics to solve the problem and then verify your answer using the simulation. Assume that the acceleration due to gravity has a magnitude of g = 9.80 m/s2. If the range of the projectile is 5.96 m, the time-of-flight is T = 1.20 s, and air resistance is turned off, determine the following. A. What is the launch angle of the projectile? B. What is the initial speed of the projectile? C. Express the maximum height reached by the projectile in terms of g and T (the time-of-flight). h_max = "Please show detailed work" I am trying to figure out how to do this for future problems."

Two charges are placed on the x axis, +5 μC at the origin and −10 μC at x = 5 cm. (a) Find the electric field on the x axis at x = 3 cm. N C x̂ (b) At what point on the x axis is the electric field zero? cm

A person walks due north for 1 km then west for 1.5km then southwest for 2.5km. Draw each displacement then find the total displacement using head to tail method.

An Airplane flys southwest for 100km then east for 75km. What is the total displacement using component method of addition?

Please show all work

Two blocks of masses m and 3m are placed on a frictionless, horizontal surface. A light spring is attached to the more massive block, and the blocks are pushed together with the spring between them as shown in the figure below. A cord initially holding the blocks together is burned; after that happens, the block of mass 3m moves to the right with a speed of v with arrow3m = 1.70 m/s.

(a) What is the velocity of the block of mass m? (Assume right is positive and left is negative.) _____ m/s

(b) Find the system's original elastic potential energy, taking m = 0.380 kg. _____ J

(c) Is the original energy in the spring or in the cord? in the spring in the cord

(d) Explain your answer to part (c). .

(e) Is the momentum of the system conserved in the bursting-apart process? Yes No

(f) Explain how that is possible considering there are large forces acting. (g) Explain how that is possible considering there is no motion beforehand and plenty of motion afterward?