Physics - October 2007

please could you make it simple, and that is do able in 1 hr or less that doesn't need like complex materials.
Thanks!

2007-10-28 16:12:15 · 2 answers · asked by ninja turtle 1

2007-10-28 16:02:31 · 9 answers · asked by nancy c 1

The balls are a tennis ball, a golf ball, and a rubber bouncy ball.
Based on the concept of elastic potential energy

2007-10-28 15:52:55 · 4 answers · asked by ... 4

non uniform acceleration
the jerk motion is defined as the rate of change in velocity with time
a)write the equation which defines the average jerk with time
b)write the units for the average jerk
c)and tell me how to sketch a graph of jerk vs time ( for the carts motion )

2007-10-28 15:46:47 · 2 answers · asked by ashanti j 1

1. a 63-kg skier coasts up a snow-covered hill that makes an angle of 25 degrees with the horizontal. the initial speed of the skier is 6.6 m/s. after coasting a distance of 1.9 m up the slope, the speed of the skier is 4.4 m/s. [A] find the work done by the kinetic frictional force that acts on the skis. [B] what is the magnitude of the kinetic frictional force?


2. a water slide is constructed so that swimmers, starting from rest at the top of the slide, leave the end of the slide traveling horizontally. as the drawing shows, one person hits the water 5.00 m from the end of the slide in a time of 0.500 s after leaving the slide. ignoring friction and air resistance, find the height H in the drawing.

* sorry about the second question. i cant really draw the picture. but the answer for that question is 6.33 m. i dont know how they got that. :[[

2007-10-28 15:42:42 · 1 answers · asked by Amy C 1

a brick is positioned first with its largest surface in contact with an inclined plane. the plane is tilted at an angle to the horizontal until the brick just begins to slide, and the angle,0, of the plane with the horizontal is measured. then the brick is turned on one of its narrow edges, the plane is tilted, and 0 is again measured. predict whether there will be a difference in these measured angles.

2007-10-28 15:42:09 · 3 answers · asked by aznedisonx 3

sulfur with iron mixed up, and iron (II) sulfide...

it states that matter is not created nor destroyed, the mass of combination before and after heating (sulfur with iron) should have been the same. What could have caused the % difference?

2007-10-28 15:27:19 · 4 answers · asked by Juan C 6

A container of volume V = 1.9 litres has a mass of 51.028 g when evacuated. When the container is filled with air pressure p = 3.4 atm at a temperature T = 30oC, what is the mass of the system? Treat air as an ideal gas with molar mass M = 28.25 g/mol.
Express the result in the unit [g] and to three significant figures. If you must use scientific notation, please enter as follows: e.g. 0.000123 = 1.23E-4. Please show all calculation steps so that I understand how the answer is determined

2007-10-28 15:22:57 · 2 answers · asked by Penny M 1

Could it actually change

2007-10-28 15:16:04 · 4 answers · asked by rst41 2

Sodium ions (Na+) moave at 0.794 m/s through a bloodstream in the arm ofa person standing near a large magnet. The magnetic force has a strength of 0.26T and makes an angle of 69 degrees with the motion of the sodium ions. The arm contains 61.3 cm3 of blood (within the magnetic field) with 1.41 x 10^20 Na+ / cm3. If no other ions are present in the arm, what would be the magnetic force on the arm? Answer in units of N.

2007-10-28 15:01:48 · 1 answers · asked by Anonymous

a tennis ball is thrown vertically upward with an initial velocity of +8.0 m/s
A)what will the balls speed be when it reaches its starting point
B)how long will the ball take to reach its starting point

please solve and show your work, i would like to understand how this problem works as it is the only one in the section that i don't understand

2007-10-28 14:39:34 · 3 answers · asked by Anonymous

The container is filled with water to level h. What is the volume of water in the container (in terms of h and a)?
What is the area of the surface of the water when filled to level h (in terms of h and a)?
The water is evaporating from the container at a rate proportionate to the surface area, with proportionality constant k. Approximate the time t in which the water level drops from to level h (in terms of h, Δh, a, and k). Assume that Δh is small, and that the rate doesn’t change much during this time.
If the water is initially filled to level H, how long will it take to completely evaporate?
I need to show all my work thanks

2007-10-28 14:39:24 · 2 answers · asked by ironmanfb12 1

how many of H2O i dumped will be in the cup after you scooped it from the ocean?

2007-10-28 14:24:26 · 4 answers · asked by ritushstar 1

A balloon is rising at a constant speed of 5ft/sec. A boy is cycling along a straight road at a speed of 15 ft/sec. when he passes under the balloon, it is 45 ft above him. How fast is the distance between the boy and the balloon increasing 3 seconds later?

2007-10-28 14:23:42 · 2 answers · asked by Anonymous

Need help with this word problem:
Shiny lawn spheres placed on pedstals are convex mirrors. One such sphere has a diameter of 40 cm. A 12-cm robin sits in a tree 1.5 m from the sphere. Where is the image of the robin and how long is the image?

So far, I figured distance of object is 150cm, and height of object is 12cm, but I need more than that for the equations!!!

2007-10-28 14:16:57 · 2 answers · asked by Team_Balla 3

My assignment is to create a book to explain Newton's Laws of Motion so that a 4th grader could understand it.

2007-10-28 14:09:35 · 4 answers · asked by Anonymous

2007-10-28 13:50:00 · 2 answers · asked by piinkpolkadots 1

A proud new Honda owner drivers her car at a speed of 25 m/s into a corner. The coefficients of friction between the road and the tires are 0.70 (static) and 0.40(kinetic). What is the minimum radius of curvature for the corner in order for the car not to skid?

2007-10-28 13:45:33 · 1 answers · asked by korr 2

Answertariat:

Why can glider's glide with minimal altitude loss?

Here is my flawed reasoning for why they cannot!
Lets say we have a glider that weights 100kg flying through the air at a speed of 10m/s. Traveling at this speed, it generates a lift of ~1 kN (F = mg so it stays at constant altitude). The kinetic energy of the glider is 5kJ. Without energy entering the system, the kinetic energy should be converted into lifting force. By this reasoning, the glider should reach zero velocity in just a few meters.

Basically, it seems like the force required to keep a plane in the air is less than the force driving it at a constant velocity.

2007-10-28 13:43:23 · 2 answers · asked by TSSA! 3

Calculate the force of gravity on a spacecraft 32000 km (5 earth radii) above the Earth's surface if its mass is 1900 kg.

______________N (toward the earth)

2007-10-28 13:30:19 · 1 answers · asked by hayleym425 2

and back. The static coefficients of friction between his shoes and the wall, and between his back and the wall, are 0.73 and 0.57, respectively. What is the minimum normal force he must exert? Assume the walls are vertical and that friction forces are both at a maximum. Ignore his grip on the rope.

2007-10-28 13:15:30 · 1 answers · asked by Doc 2

(Time and Space) paradox question?
Question Details: if a person was traveling to Earth from a distant point 500 light-years away and they were traveling at the speed of light, to the person on Earth would it seem to take the traveler 500 years to reach here? and to the traveler would it still seem and appear to him to take 500 years to reach Earth, even though to a person on Earth the traveler wouldn't have seemed to "age"? understand the question? by the person on Earth's time standards, to and from back to Earth at the speed of light, would appear not to age the traveler 500 years, so does the traveler experience the 500 year time spance traveling at the speed of light?

2007-10-28 12:53:33 · 3 answers · asked by Courageous Capt. Cat 3

Consider two ways that light might hypothetically get from its starting point S to its final point F by way of a mirror: by reflecting from point A or by reflecting from point B. (L = 24 cm) Since light travels at a fixed speed in air, the path of least time will also be the path of least distance. Show by calculation that the path SBF is shorter than the path SAF.
_____cm (path SBF)
_____cm (path SAF)

2007-10-28 12:51:35 · 1 answers · asked by w_rayas07 1

At what point does the point lose contact with the dome? Thorough explaination please. I remember doing this back in classical mechanics and saw it in a trade magazine about a year ago. Its been driving me nuts ever since.

2007-10-28 12:41:01 · 1 answers · asked by rocketscientistnate 1

Moving in the same direction at 20 cm/s. Find the velocity of the object which is slower after the collision. Answer in units of cm/s.

2007-10-28 12:23:40 · 1 answers · asked by mira s 1

If you stopped the world spinning and spun it the opposite direction

2007-10-28 11:45:57 · 10 answers · asked by mystic witch 2

I'm curious. When it's not got the computer monitor behind it looks like it's vibrating at the same speed no matter what pitch I change it to, but when I look at the string in front of the monitor, it appears to slowly... sort of swim, like a sperm tail would, and it changes at different pitches. Why does a computer monitor do this?

2007-10-28 11:43:52 · 2 answers · asked by Chris 3

What is a definition for a compound pendulum?
its urgent!!!

2007-10-28 11:34:57 · 2 answers · asked by |Earth| |Air| |Fire| |Water| 2

Calculate the force of gravity on a spacecraft 32000 km (5 earth radii) above the Earth's surface if its mass is 1900 kg.

____________N (toward the earth)

(I can't figure this out! I know I have the right equation but it just isn't working!) Please HELP!

2007-10-28 11:29:43 · 1 answers · asked by hayleym425 2

and leaves at a pressure of 2.82×10^5 Pa. What must the celsius temperature of the compressed air be for there to be no possibility of frost forming in the exhaust ports of the engine? Assume that the expansion is adiabatic. (Note: Frost will form if the moist air is cooled below 0 degrees celsius in the expansion.)

2007-10-28 11:19:09 · 1 answers · asked by Paul C 1