Physics - November 2007

If two starships fly away from each other with speeds 0.6c (that is 60% of speed of light) each, at what rate the distance between the ships increases?

2007-11-07 09:33:42 · 3 answers · asked by Alexander 6

In Example 10.5 (Section 10.3) we found that for a hollow cylindrical shell rolling without slipping on a horizontal surface, half of the total kinetic energy is translational and half is rotational. What fraction of the total kinetic energy is rotational for the following objects rolling without slipping on a horizontal surface?
(a) A uniform solid cylinder.

(b) A uniform sphere.

(c) A thin-walled hollow sphere.

(d) A hollow, cylinder of outer radius R and inner radius R/2.

*I thought I was looking right at the chart the question was talking about but I still am getting wrong answers!!!

2007-11-07 09:27:26 · 1 answers · asked by Walachka 3

Work done by the battery
Work = UQ = 1 Joule
Energy strored in capacitor according to my textbook
Energy = 1/2 CU² = 1/2 Joule

Where did 1/2 Joule of energy disappear?

2007-11-07 09:26:24 · 1 answers · asked by Alexander 6

I need a lot of science fomulas.
Like force, and momentum, and acceleration, and velocity, and speed, and kinda anything relating to that suff.
Please help?!

2007-11-07 09:24:29 · 1 answers · asked by Smuckers 4

Question: Find the point between Saturn and the Sun at which an object can be placed so that the net gravitational force exerted by Saturn and Sun on this object is zero.

mass of sun: 1.991 x 10^30
mass of saturn: 5.68 x 10^26
distance between sun and saturn: 1.43 x 10^12

i set the forces equal to each other
GmMsun/r^2 = GmMsaturn/ (d-r)^2

where d is the distance between the two.

I cancelled out common terms and got
Msun/r^2 = Msaturn/ (d-r)^2

I plugged in the values and then tried to solve for r using the quadratic equation, butI kept getting a nonreal answer. any help would be appreciated!

2007-11-07 09:13:17 · 2 answers · asked by Katlyn G 1

The x- and y-components of an acceleration vector are 3.0 m/s2 and 4.0 m/s2 respectively.
What is the direction of the acceleration vector (in degrees)?

2007-11-07 08:54:22 · 1 answers · asked by Anonymous

A car with a velocity of 27 m/s slows down at a rate of - 8.5 m/s2 to a stop in a distance
of 43 m on a dry road. The same car traveling at 27 m/s slows down at a rate of -6.5 m/s2 to a stop on a wet road.
a. How much farther does the car travel on the wet road before coming to a stop?
b. What maximum car speed will allow the car traveling on the wet road to stop in a distance of 43 m?


. A car traveling at 14 m/s encounters a patch of ice and takes 5.0 s to stop.
a. What is the car’s acceleration?
b. How far does it travel before stopping?


THANKS

2007-11-07 07:29:09 · 2 answers · asked by Bill B 1

I only did a year of genetics at University and that was 22 years ago!!!

I've been working in an inquiry primary curriculum since then...so...

My 7 year old son and I are working on proving (or disproving) the hypothesis that "everything we percieve is energy" vibrating at different frequencies.

Tonight, I caught him trying to see if he could make a magnetic chamber to charge (and test!) his crystal collection!!

I think it's time I got some expert input?!!
All insights welcome!

2007-11-07 07:20:51 · 6 answers · asked by Swissinquirer 2

I'm stuck on this question, where do I find the force, AS Physics, thanks.

2007-11-07 07:16:43 · 2 answers · asked by Anonymous

i dont kno the equations for angular momentum

2007-11-07 06:55:33 · 4 answers · asked by Anonymous

a car of mass 600 kg accelerates from rest to 8m/s in 40s.
i find that resultant force on car in 120N

so: if car is fitted with trailer mass 100kg, find time taken to accelerate to 8m/s.

assuming that F is 120N,
the textbook answer is:
F=ma
F=m x (v-u)/t

t=(mv-mu)/F
=(700x8)/120
= 46.7seconds.
what i need to understand is how F=ma got into that if the car is with a trailer. and why is there a momentum equation?

thanks T^T

2007-11-07 05:42:15 · 3 answers · asked by supernovastarfish 1

2007-11-07 05:22:56 · 2 answers · asked by David L L 2

In an aortic aneurysm, a bulge forms where the walls of the aorta are weakened. If blood flowing through the aorta (radius 1.0 cm) enters an aneurysm with a radius of 3.1 cm, how much on average is the blood pressure higher inside the aneurysm than the pressure in the unenlarged part of the aorta? The average flow rate through the aorta is 110 cm3/s. Assume the blood is non-viscous and the patient is lying down so there is no change in height.
___ Pa

2007-11-07 04:20:35 · 2 answers · asked by Pr0ject 1

i need to know for my science show

2007-11-07 03:56:40 · 3 answers · asked by Anonymous

A rod suspended on its end and acting as a physical pendulum swings with a period of 2.26 s. What is its length? (g = 9.80 m/s^2)

2007-11-07 03:48:22 · 2 answers · asked by Jerry M 1

How much electric power could be obtained from a small hydroelectric station if the elevation change was 150 meters and if 10, 000 kg of water passed through the turbines every second, with the overall efficiency being 85 %?

support your answer with equation.

2007-11-07 03:47:35 · 2 answers · asked by Anonymous

An airplane flies on a level path. There is a pressure difference of 525 Pa between the lower and upper surfaces of the wings. The area of each wing surface is about 112 m^2. The air moves below the wings at a speed of 80 m/s. Find the air speed above the wings if the weight of the plane is 117600 N.

2007-11-07 03:45:27 · 3 answers · asked by Jerry M 1

a 5.00 kg block is pulled along a horizontal frictionless floor by a cord that exerts a force of magnitude F=12.0 N at an anglr of 25 degrees above the horizontal. What is the magnitude of the block's acceleration? the force magnitude F slowly increased. What is its value just before the block is lifted (completely) off the floor?
what is the magnitude of the block's acceleration just before is lifted off the floor (completely.

2007-11-07 03:38:26 · 4 answers · asked by magna1211@sbcglobal.net 1

This is a scientific question. Meaning that this is for a Science Fair Project. Answer as adequately as you can

2007-11-07 03:32:12 · 12 answers · asked by Anonymous

A lever is used to lift a heavy load. When a 50-N force pushes one end of the lever down 1.2 m, the load rises 0.2 m. Calculate the weight of the load

2007-11-07 03:31:03 · 1 answers · asked by Anonymous

As you drive down the road at 20 m/s you press on the gas pedal and speed up with a uniform acceleration of 1.16 m/s2 for 0.70 s. If the tires on your car have a radius of 33 cm, what is their angular displacement during this period of acceleration?

2007-11-07 03:27:02 · 6 answers · asked by Amber G 2

The second floor of a house is 6 m above street level. How much work is required to lift a 300-kg refrigerator to the second floor level?

2007-11-07 03:18:51 · 1 answers · asked by Anonymous

2007-11-07 02:04:54 · 9 answers · asked by Abdul Khalid 1

what materials whould i have to use?
I need to create it as part of an architecture project, so i can put metalic items in the field and investigate their movement

2007-11-07 02:02:11 · 5 answers · asked by STEPHANOS C 1

2007-11-07 01:33:53 · 1 answers · asked by Anonymous

or how can we say that violation of any one of these leads to the violation of other one

2007-11-07 01:27:56 · 1 answers · asked by gini 1

A skater has a moment of inertia of 5 kg-m² when her arms are outstretched and 2 kg-m² when they are later brought to her sides. If she starts spinning at 3 radians/s, what is her final angular speed?

2007-11-07 01:23:19 · 1 answers · asked by hazel200012000 1

From an initial rate of 15 rad/s, a wheel is uniformly accelerated to 25 rad/s after 5 seconds. What is its constant angular acceleration?

2007-11-07 01:20:38 · 1 answers · asked by Anonymous

A 40 kg girl who is running at 2.5 m/s jumps on a stationary 10 kg sled on a frozen lake. How fast do she and the sled then move?

2007-11-07 01:19:49 · 1 answers · asked by Anonymous

The question has 6 different parts but please help...we haven't even covered this yet!

1) A ball of mass 20.0 g is launched horizontally from a height of 2.20 m. It is observed to travel 3.15 m horizontally. What was the initial speed of the ball?

2) What is the initial momentum of the ball?

3) What is the initial kinetic energy of the ball?

4) If the ball is instead launched at a pendulum of mass 144.0 g and makes a perfectly inelastic collision, how fast is the pendulum+ball going immediately after the collision?

5) What is the kinetic energy of the pendulum+ball immediately after the collision?

6) What is the maximum height obtained by the pendulum+ball?

2007-11-07 01:08:08 · 2 answers · asked by hmm 1