Physics - November 2007

2007-11-13 15:00:31 · 4 answers · asked by arbederi 1

What is the actual definition of "gravity." We all know how gravity works and it's effects. But nobody really "knows" what gravity is and why large masses attract other masses.

2007-11-13 14:50:13 · 10 answers · asked by Kenton C 4

2. Given λ = 469.8[nm] and θ = 37.9°, then what is the index of refraction to the nearest hundredth?
(Assume Φ=60°.)

PLEASE HELP AND EXPLAIN STEP BY STEP I HAVE OTHER PROBLEMS LIKE THIS, THANKS

2007-11-13 14:40:35 · 1 answers · asked by Anonymous

ok i have 2 pics of my balloon car:

http://i60.photobucket.com/albums/h25/gg-unotsucks/PHOT0008.jpg

http://i60.photobucket.com/albums/h25/gg-unotsucks/PHOT0007.jpg

i blow the balloon(rubber glove) and it doesnt go anywhere.

what should i do, it only wieghs less than a pound.

2007-11-13 14:34:11 · 1 answers · asked by gman919 2

Where does the car's kinetic energy go when the parachute is let out behind it? Does it go to the parachute, the ground from the car's friction, etc?

Thanks in advance.

2007-11-13 14:33:07 · 1 answers · asked by Anonymous

A 1.6kg object moving at a speed of 8.9m/s strikes a 1.2 kg object intially at rest. Immediately after the collision, the 1.6kg object has a velocity of 1.3m/s directed 21 degrees from its intial line of motion. What is the speed of the 1.2kg object immediately after the collision. Answer in m/s.

2007-11-13 14:26:28 · 1 answers · asked by akanthasy 1

2007-11-13 14:10:48 · 2 answers · asked by Anonymous

lets say there are two situations...
gymnast A has more mass than gymnast B
If they both do a flip will gymnast B (the lighter one) have a harder time landing/stopping considering inertia?
If something has a large mass they have a large inertia, right?
So wouldn't the lighter guy have a larger resistance in changing his direction of motion (I basically just said will he have a harder time sticking the landing)?

Also, how do you explain the concepts of weight and gravity in gymnastics when doing a flip?

2007-11-13 14:01:03 · 5 answers · asked by --->♥<--- 2

A 24 kg crate initially at rest on a horizontal surface requires a 75 N horizontal force to set it in motion. Find the coefficient of static friction between the crate and the floor.

2007-11-13 13:56:02 · 3 answers · asked by mega4life2000 1

https://elearning.courses.ufl.edu/webct/RelativeResourceManager?contentID=774325562021

What would the maximum velocity be? It's been years since I've taken a trig class..i don't have a clue

2007-11-13 13:51:49 · 4 answers · asked by davidbbk 1

The wavelength of a water wave is 8.0m and its speed is 2.0m/s. How many waves will pass a fixed point in the water in 1.0min?

2007-11-13 13:43:37 · 1 answers · asked by jasminder 2

it doesnt make sense

2007-11-13 13:40:24 · 4 answers · asked by Anonymous

2007-11-13 13:36:07 · 4 answers · asked by ashu 1

There is a biker riding constant velocity at k m/s the distance is traveled in t seconds given by the function d(t)=kt. There is a support car that starts when it passed and catches up so when it does it is traveling at the same speed its function is given by s(t)=6t^2-t^3. When the car catches up it immediately slows down. I've figured k=8m/s and t=2sec.

Suppose the biker is riding at a constant velocity (v) which can be different then k.

What is the expression that gives the time or times the car and the bike meet in terms of v?

2007-11-13 13:34:39 · 1 answers · asked by dcwest20 1

A long jump shot is released 2.1 m above the ground, 5.96 m from the base of the basket, which is 3.05 m high. For launch angles of 30° and 60°, find the speed needed to make the basket.

2007-11-13 13:34:25 · 1 answers · asked by lamz 1

a satellite of the earth has a mass of 100kg and its altitude of 2,000,000 m what is the potential energy of the satellite-earth system?
what is the magnitude of the gravitational force exerted by the earth on the satellite and what is the gravitational force does the satelite exert on the earth?

2007-11-13 13:33:53 · 1 answers · asked by Anonymous

How high does a rocket have to go above the
Earth's surface so that its weight is reduced
to 73.2% of its weight at the Earth's sur-
face? The radius of the Earth is 6380 km
and the universal gravitational constant is
6.67e-11 N *m^2/kg^2. Answer in units of
km.

2007-11-13 13:32:24 · 1 answers · asked by Anonymous

2007-11-13 13:25:05 · 3 answers · asked by ashu 1

#1. A parallel plate capacitor of capacitance C sub zero has plates of area A with separation d between them. When it is connected to a battery of voltage Vsub0, it has charge of magnitude Qsub0 on its plates. The plates are pulled apart to a sepatation 2d while the capacitor remains connected to the battery. After the plates are 2d apart, what is the magnitude of the charge on the plates and the potential difference between them?
#2. A proton with a charge +e is moving with a speed v @ 50degrees to the direction of magnetic field B. The component of the resulting force on the proton is the direction of B is?
#3. In a loop in a closed circuit, the sum of the current entering a junction equals the sum if the currents leaving a junction because??
#4. Two wires of the same material with the same lenght have differenct diameters. Wire A has twice the diameter of wire B. If the resistance of wire B is R, then that is the resistance of wire A?

2007-11-13 13:22:18 · 1 answers · asked by none 1

An 62.0 N box of clothes is pulled 5.6 m up a 30.0° ramp by a force of 95 N that points along the ramp. If the coefficient of kinetic friction between the box and the ramp is 0.22, calculate the change in the box's kinetic energy.

Can u show me what to do???



How long will it take a 1620 W motor to lift a 285 kg piano to a sixth-story window 16.0 m above? again please

2007-11-13 13:13:29 · 1 answers · asked by Anonymous

I've heard from some friends of mine that physics can't understand how bees fly. That the math just says they shoudn't be able to fly. Is that true? If so how do they fly then?

2007-11-13 13:06:12 · 7 answers · asked by Eric 2

2007-11-13 13:03:04 · 1 answers · asked by Anonymous

three particles each of mass 5g each located at a corner of equilateral triangle with side length of 30cm
what is the potential energy of the system

2007-11-13 12:59:43 · 2 answers · asked by MeNeedHelp 2

Please dont guess...i will give ten points to the first good one
2. Larger wings on a plane create what?
3. Why can a steel ship float?
4.what makes an object sink?
5. Buoyant force is _______ to the weight of the water is displaces.
6. How does pressure affect the flow of fluids?
9. What affects the amount of lift on an airplane's wing?
10. Where is atmospheric pressure be the greatest?
11.How does the design of a wing enable a plane to fly?
12. What does bernoulli's state(in your own words)
13.What does pascals principle state(in your own words)
14 Why do jet pilots wear pressurized suits?
15. Why does a tire expand when you pump air into it?
17. what is a hydraulic lift? how does it work?
20. Using Bernoulli's principle, what is net force?

2007-11-13 12:52:53 · 1 answers · asked by Anonymous

A small rubber wheel is used to drive a large pottery wheel, and they are mounted so that their circular edges touch. Assume that the small wheel has a radius of 2.0 cm and accelerates at the rate of 7.2 rad/s2, and it is in contact with the pottery wheel (radius 25.0 cm) without slipping.

1)Calculate the angular acceleration of the pottery wheel. (rad/s2)
2)Calculate the time it takes the pottery wheel to reach its required speed of 61 rpm.(s)

2007-11-13 12:47:56 · 1 answers · asked by Corey S 1

Compared to some original speed, how much work must the brakes of a car supply to stop a car moving four times as fast? How will the stopping distance compare?

2007-11-13 12:46:42 · 1 answers · asked by Anonymous

Assume that during each pulse a mammalian heart accelerates 21 g of blood from 18 cm/s to 28 cm/s during a time interval of 0.10 s. Calculate the magnitude of the force (in newtons) exerted by the heart muscle on the blood.

2007-11-13 12:45:40 · 2 answers · asked by To-the-Stars 4

I guess my real question is "Is it possible to control the roll of a rocket using one gimballed thruster at the base of the rocket?"

2007-11-13 12:43:00 · 1 answers · asked by yatpay 1

A linearly polarized electromagnetic wave is sent through two sheets of polarizing material. The first sheet,A, is oriented so that its transmission axis makes an angle of 30deg with respect to the incident electric field of the wave. The second sheet,B, is oriented so that its transmission axis makes an angle of 90deg with the incident electric field of the wave. The incident beam has an electric field of peak magnitude Esubscript0 and average intensity Ssubscript0.

a) What is the peak value of the electric field amplitude after it goes through sheet A?

b) What is the average intensity of the wave after it passes through A?

c) What is the average intensity of the wave after it passes through B?

d) Suppose that A and B are interchanged so that the wave is first incident upon B. What is the average wave intensity after passing through both polarizing sheets?

2007-11-13 12:18:51 · 1 answers · asked by Steph C 1

It takes a 615-kg race car 14.3 s to travel at a uniform speed around a circular racetrack of 50.0 m radius .

What is the acceleration of the car?

What average force must the track exert on the tires to produce this acceration?

2007-11-13 12:09:38 · 2 answers · asked by james 2