Physics Answers

The brakes of a car provide an acceleration of 5.0m/s^2. How long will it take for a car traveling at 20 m/s to stop

Find the total capacitance for three capacitors connected in series, given their 

individual capacitances are 1.000, 5.000, and 8.000 µF. (0.755µF)

starting from rest a car accelerates at 2.0 m/s^2. How far will it go after 6.0 s

Define the relative refractive index difference for an optical fiber and show how it

May be related to the numerical aperture. A step index fiber with a large core diameter compared with the wavelength of the transmitted light has an acceptance angle in air of 22° and a relative refractive index difference of 3%. Estimate the numerical aperture and the critical angle at the core–cladding interface for the fiber.

3. Measurements show that 500 muon fall on the top of Mt. Washington altitude 2000m. Muons travel at 99% the speed of light or 0.99 x 3.0 x 10⁸ m/s.

a. Calculate the time in microseconds it would take muon to travel from the top of mt. Washington to its base.

b. Use your calculation and the muon clock graph to find how many muons should reach the bottom of Mt. Washington.

4. Experiments show that the actual number of muons that reach the base of Mt. Washington is 400.

a. According to your muon clock graph, how much time has elapsed if 400 muons reach the base of Mt. Washington?

b. By what factor do the times you found differ?

c. Suggest an explanation for this difference.

2. The half-life of muons provides you with a muon clock. Plot a graph of the number of muons versus time. Use 500 muons as the size of the sample. This graph will become your clock.

a. If 125 muons remain, how much time has elapsed?

b. If 31 muons remain, how much time has elapsed?

c. If 300 muons remain, how much time has elapsed?

d. If 400 muons remain, how much time has elapsed?

Calculate the energy stored in elastic material with K=1500NM and applied force at 750N

What is the magnitude of the force that a 25μC-charge exerts on a 10μC charge {\rm 8.5\, cm}8.5cm away? (Take k=9×106^9 N.m^2/C^2)

What is the magnitude of the force that a 25μC-charge exerts on a 10μC charge {\rm 8.5\, cm}8.5cm away? (Take k=9×109 N.m2/C2)

A tesla car needs to charge its 350-volt model and must send about 715 amps through its cabling to the battery. What is the rate of electron flow through the cable for the current involved?