Physics - January 2007

A swimmer is 1.8 meters tall. She dives into the pool and swims her race with a constant acceleration of .25m/^2. How long does it take her to pass the backstroke flags that are 20 meters away?


When I did it, i got 13.2 seconds. Could someone who is good at physics please check it and see if i did it wrong? Thanks so much.

2007-01-25 12:30:47 · 6 answers · asked by Jane A 3

2007-01-25 12:23:19 · 4 answers · asked by Anonymous

Airplane A, starting from rest with constant acceleration, requires a runway 400 m long to become airborne. Airplane B requires a takeoff speed twice as great as that of airplane A, but has the same acceleration, and both planes start from rest.

a) How long must the runway be for airplane B?
Answer for this part was 1600 meters! What is part B?

b) If airplane A takes time 'T' to travel the length of its runway, how long (in terms of 'T') will airplane B take to travel the length of its runway?

2007-01-25 12:15:29 · 3 answers · asked by skooobie 1

An electron is released from rest in a uniform electric field of magnitude 2.20 104 N/C. Calculate the magnitude of the acceleration of the electron. (Ignore gravitation.)

2007-01-25 12:11:12 · 2 answers · asked by a.m. 1

i was wondering if there was any way i could get a better signal in my room, i was wondering if tinfoil would deflect wifi waves and if not, what will?

2007-01-25 11:59:44 · 2 answers · asked by John S 2

what is it about light that makes people think nothing goes faster then it. what about time what speed does time travel at .
please explain this at about a grade 4 level i really dont know any thing about how people came up with this idea of light being the fastest.

2007-01-25 11:55:27 · 24 answers · asked by Anonymous

2007-01-25 11:30:03 · 5 answers · asked by josephahn72 2

since the microscopic make up everything. shouldn't they exist on all levels?

2007-01-25 11:23:04 · 5 answers · asked by Anonymous

2007-01-25 11:12:45 · 3 answers · asked by marc 2

A 7 kg block being pulled across a table by a horizontal force of 40 N also experiences a frictional force of 10 N. What is the acceleration of the block? m/s2

2007-01-25 11:12:02 · 2 answers · asked by bibun 2

115.0 ml of milk at 20.0oC are added to 459.5 ml of coffee at 93.6oC . What is the final centigrade temperature of this liquid mixture when thermal equilibrium is reached ?


Assume coffee has the same properties as pure water.


The average density of milk is 1032 kg/m3


The specific heat of milk is 1.97 J/g-oC

2007-01-25 11:10:09 · 2 answers · asked by nietzsche 1

If the hour and minute hands on a clock have a common axis of rotation and equal mass and the minute hand is long and thin whilst the hour hand is short and thick, which has a greater moment of inertia?

I thought the hour hand would have the greater moment of inertia because it's heavier, but I'm not really sure. Does anybody else have ideas?

2007-01-25 10:50:56 · 4 answers · asked by Anonymous

2007-01-25 10:50:12 · 7 answers · asked by chriskelly003 1

An electron beam in an oscilloscope is deflected by the electric field produced by oppositely charged metal plates. If the electric field between the plates is 2.75 105 N/C directed downward, what is the force on each electron when it passes between the plates?

2007-01-25 10:43:49 · 3 answers · asked by David S 2

A massive truck collides with a small spot car. which vehicle experiences the greater force of impact?

2007-01-25 10:31:11 · 12 answers · asked by argentina 1

Two identical conducting spheres carry charges of +5.4 µC and -1.4 µC respectively. They are initially a large distance L apart. The spheres are brought together, touched together, and then returned to their original separation L. What is the ratio of the magnitude of the force on either sphere after they are touched to that before they were touched?

2007-01-25 10:16:31 · 5 answers · asked by David S 2

I welcome all scientific explanations.Thanks!!

2007-01-25 10:15:45 · 6 answers · asked by Tboz 1

that makes an angle of 31 degrees with the horizontal?

2007-01-25 09:12:00 · 3 answers · asked by lillisrj 2

I am having a hard time with this-could someone at least get me started?
A particle of mass m is traveling at an initial speed v0 = 27.0 m/s. It is brought to rest in a distance of 51.0 m when a net force of 16.0 N acts on it. What is m?

2007-01-25 08:59:54 · 3 answers · asked by Froggiesmiles 3

Aim;To find how the current through a conductor varies with the potentoal difference between its ends

2007-01-25 08:59:23 · 6 answers · asked by D@ni DiC@prio 4

If a person was in a vehicle that would accelerate faster at a slow rate, and slow down, but still maintain some of the additional velocity from the fast acceleration, and alternated this process
for awile, could the vehicle eventually reach a very fast velocity, and the passenger would not experience a large gravity factor (not many g's)?

2007-01-25 08:51:37 · 4 answers · asked by Michael n 2

Will the light stay on and continue to bounce from mirror to mirror??

2007-01-25 08:26:02 · 5 answers · asked by Anonymous

and not roll over onh its side, and why does this happen?

2007-01-25 08:25:19 · 8 answers · asked by Anonymous

2007-01-25 08:21:46 · 23 answers · asked by Anonymous

how much influence over our daily lives does the moon really have?

2007-01-25 08:21:24 · 2 answers · asked by Mystee_Rain 5

e.g. the big bang came from a sigularity and a god gives life and death to everything apparently, but as everyone knows you need energy to do this. So where did a god or a big bang get the energy to do this, if things are not infinite.

2007-01-25 08:09:50 · 11 answers · asked by zeroinfinity121 1

What are the magnitude and direction of the acceleration of an electron at a point where the electric field has magnitude 6100 N/C and is directed due north?

2007-01-25 07:43:37 · 2 answers · asked by David S 2

If the electrical force of repulsion between two 1 C charges is 10 N, how far apart are they?

2007-01-25 07:41:38 · 1 answers · asked by David S 2

2007-01-25 07:40:42 · 7 answers · asked by sorida 1

I was just wondering what Einstein did that was so great. I understand that he did the whole E=mc2 thing and what it stands for, but i dont understand why it was so great. And did he do anything else to help the world?

2007-01-25 07:40:26 · 5 answers · asked by mrfuzzy64 1