Homework Help for Physics

You should have observed in Activity 26.5.2 that a permanent magnetcan exert forces on moving charges or currents.

(a) If a magnet exerts a force on a moving charge would the magnetexperience any forces? Explain
(b) In the case of the gravitational or electrostatic interactionbetween two objects, each object has a common property such as massin the case of gravitational interaction or excess charge in thecase of the electrostatic interaction. A permanent magnet and amoving electron seem very different. Can you think of any way thatthey might have a common property? Explain.

Initially a wheel rotating about a fixed axis at a constant angular deceleration of 0.9 rad/s^2 has an angular velocity of 0 rad/s and an angular position of 9 rad. What is the angular position of the wheel after 2.5s?

Are the antinode amplitudes the same for all five harmonics for a given tension

A highway curve has a radius of 120m. At what angle should the road be banked so that a car traveling at 27.8 m/s has no tendency to skid sideways on the road? Hint: no tendency to skid means the frictional force is zero. Please show all work.

A satellite orbits the earth (mass = 5.98 e24 kg, r of earth = 6.38e3 km) at height of 4.01 e4 km. In all calculations use the correctprecision.

What is r in meters?

what is the symbolic formula to solve the satellitesvelocity?

Enter the values in the equation and solve the value of v.

What is the distance around the orbit in meters?

What is the formula to find the period?

What is its orbital period in seconds?

What does that convert to in days?

Please show all work

1)Would thestanding wave patterns be altered if strings weredispersive?
2) What would you expect the standing wave pattern to look like ifexperiment used a composite string made of half thick string andhalf thin string tied end to end? Draw a picture showing thepattern.

An astronaut stands at a position on the Moon such that Earth isdirectly over head and releases a Moon rock that was in herhand.
(a) Which way will it fall? answer toward moon

What is the gravitational force exerted by the Moon on a 1.4-kgrock resting on the Moon's surface? answer is 2.27 N

What is the gravitational force exerted by the Earth on the same1.4-kg rock resting on the surface of the Moon? answer is 3.78mN

What is the net gravitational force on the rock? answer is 2.26Ntowards the moon

please show work to get answers

A helium-neon laser beam has a wavelength in air of 633 nm . Ittakes 1.28 ns for the light to travel through 29.0 cm of an unknownliquid.

What is the wavelength of the laser beam in the liquid?
Express your answer with the appropriate units.
λ_liquid = ___________

The human eye can readily detect wavelengths from about 400 nmto 700 nm .

If white light illuminates a diffraction grating having 730lines/mm , over what range of angles does the visible m = 1spectrum extend?

Express your answers using three significant figures separatedby a comma.
θ_min, θ_max= ____________degrees

In a Beams ultracentrifuge, a 19.5 cm long rotor is suspendedmagnetically in a vacuum. Since there is no mechanical connectionto the rotor, the only friction is the air resistance due to thefew air molecules in the vacuum. If the rotor is spinning with anangular speed of 4.8 105 rad/s and the driving force is turned off,its spinning slows down at an angular rate of 0.39 rad/s2.
(a) For a point at the end of the rotor, find the initialspeed.
answer is 0.936 e5 m/s

(b) For a point at the end of the rotor, find the tangentialacceleration component.
answer is 0.0761 m/s2

(c) For a point at the end of the rotor, find the maximum radialacceleration component.
answer is 4.49e+10m/s2

Consider a bacterium, idealized as a sphere of radius 1 micron, propelling itself at 1 microm/s. At time zero, the bacterium suddenly stops swimming and coasts to a stop, following Newton

Your heart pumps blood into your aorta. The maximum flow rateinto the aorta is about 500 cm3 s-1. Assume the aorta has diameter2.5 cm, that the flow is laminar, and that the blood is a Newtonianfluid with viscosity equal to that of water (1 cP). (Note theseassumptions are rather poor.)
a) Find the pressure drop per unit length along the aorta. Expressyour answer in SI units. Compare that pressure drop along a 10 cmsection of aorta with atmospheric pressure (105 Pa).
b) How much power does the heart expend just pushing blood along a10 cm section of aorta? Compare your answer with your basalmetabolic rate, about 100 W, and comment.
c) The fluid velocity in laminar pipe flow is zero at the walls ofthe pipe and maximum at the center. Sketch the velocity as afunction of distance, , from the center. Fine the velocity at thecenter. [Hint: The total volume flow rate, which you are given,equal .]

A very thin oil film (n=1.25) floats on water (n=1.33).

What is the thinnest film that produces a strong reflection forgreen light with a wavelength of 500 nm?

d=________nm

Two steel plates are fastened together using four bolts. The boltseach have a shear modulus of 8.9 1010 Pa and a shear strength of6.0 108 Pa. The radius of each bolt is 0.9 cm. Normally, the boltsclamp the two plates together and the frictional forces between theplates keep them from sliding. If the bolts are loose, then thefrictional forces are small and the bolts themselves would besubject to a large shear stress. What is the maximum shearing forceF on the plates that the four bolts can withstand?
in N please show all work

What is the energy of a pendulum (L = 1.3 m, m = 0.5 kg)oscillating with an amplitude of 4.0 cm?
in mJ

(b) The pendulum's energy loss (due to damping) is replaced in aclock by allowing a 1.5-kg mass to drop 1.0 m in 1 week. Whatpercentage of the pendulum's energy is lost during one cycle?
please show all work