Physics - September 2007

If you can revolve an object on a string 0.7m long, at a rate of 9revolutions/second. How can you find the speed at which the object is going? Or the centripetal acceleration?

2007-09-23 04:56:14 · 2 answers · asked by Anonymous

plz help me i am getting incorrect answer
plz show working as well

3. A diver running 1.8 m/s dives out horizontally from the edge of a vertical cliff and reaches the water below 3.5 s later. How high was the cliff? How far from its base did the diver hit the water?
my answer is height of cliff = 50.23 and hits 5.76m away from base

7. Suppose the space shuttle is in orbit 416 km from the Earth's surface, and circles the Earth about once every 92.8 minutes. Find the centripetal acceleration of the space shuttle in its orbit. Express your answer in terms of g, the gravitational acceleration at the Earth's surface.
my answer 0.00540gm/s^2

8. Because the Earth rotates once per day, the effective acceleration of gravity at the equator is slightly less than it would be if the Earth didn't rotate. Estimate the magnitude of this effect, given that the radius of the Earth is 6.38 106 and that, at the equator, it rotates at 464 m/s. What percentage of g is this?
my answer 0.344%
plz help me

2007-09-23 04:41:50 · 2 answers · asked by Anonymous

I did it, but the answer doesn't seem to make much sense. Someone good at physics please just do it for me to make sure that I'm right.

A 0.2 kg rock is projected from the edge of the top of a building with an initial velocity of 9.21 m/s at an angle 43 degrees above the horizontal. Due to gravity, the rock strikes the ground at a horizontal distance of 14 m from the base of the building.

Assume: The ground is level and that the side of the building is vertical. The acceleration of gravity is 9.8 m/s^2

2007-09-23 04:35:36 · 3 answers · asked by MD12 2

In 1978, Geoff Capes of Great Britain threw a heavy brick a horizontal distance of 44.5m. Find the velocity of the brick at the highest point of its flight.

Can someone show me the steps to answering this? please.

2007-09-23 04:32:56 · 6 answers · asked by Allison S 2

2007-09-23 04:30:37 · 4 answers · asked by ☼ Jules ☼ 5

please some1 help

2007-09-23 04:14:11 · 5 answers · asked by Ã?z 1

soo cunfused :S

2007-09-23 04:13:40 · 3 answers · asked by firebyrd16 2

enric fermi
mericuri

2007-09-23 04:10:42 · 5 answers · asked by vishal aleti_rahuladhitya@yahoo. 1

The question I am given is: "A basketball star covers 2.60 m horizontally in a jump to dunk the ball (see figure). His motion through space can be modeled as that of a particle at a point called his center of mass (which we shall define in Chapter 9). His center of mass is at elevation 1.02 m when he leaves the floor. It reaches a maximum height of 1.80 m above the floor and is at elevation 0.850 m when he touches down again."

And i need to find the time of flight, the initial horizontal/vertical velocity, and angle.

However, I am pretty clueless how to find the total time. I figured x(final)=.5at^2 So sqrt((0.95*2)/a)=time, but 0.44, the answer i get (times two, so 0.88) isn't the overall hang time. Now i'm just completely lost.

2007-09-23 04:06:16 · 2 answers · asked by phrozenwarrior 3

A 85 kg water skier is being pulled at a constant velocity. The horizontal pulling force is 310 N.

(a) Find the magnitude of the total resistive force exerted on the skier by the water and air.
__________N
(b) Find the magnitude of the upward force exerted on the skier by the water.
__________N

2007-09-23 03:52:57 · 5 answers · asked by Anonymous

i wanna know cause i have this english book and i really wanna know so i will get good grades and sucess in life hoping to write a book that other students will read and become just like me and on and on and on!
tysm for ur help!

2007-09-23 03:41:22 · 8 answers · asked by Ramiboy99 2

For example velocity = (change in position)/(change in time)

2007-09-23 03:29:42 · 9 answers · asked by Anonymous

The questions asks "For what launch angle will the height and range of a projectile be equal?" I have spent over 2 hours trying to figure this question out, and the furhest I have been able to get is cos (x) = (-.5)/(v-initial)

2007-09-23 03:25:47 · 3 answers · asked by Jazzy 1

please help... I really don't know the answer..
thank you...

2007-09-23 03:16:20 · 7 answers · asked by jhenleen 1

When one lifts with all his force &gets exhausted to pick up say a 500kg weight which doesnt move at all, the output work done = (force * distance) which is zero where did the input energy go??

2007-09-23 02:49:33 · 8 answers · asked by bhushan k 1

My Science Homwork Asks Us To Find Out How Einstein Changed Arestolee's 3 Laws? Ive Looked Everywehere, Asked My Friends If They Have Found Anything. And Nobody Has..Can Anyone Help? Much Apprciated!

2007-09-23 02:18:32 · 5 answers · asked by rawk_is_my_passion 1

this is a question for my science revision. im 14 though so please dont make the answer complicated to understand!

Oh and also, aparently the steady state theory is about the origin of the universe? What is it?

2007-09-23 01:47:33 · 6 answers · asked by Anonymous

example:
exam stress..stress at school...with family..

2007-09-23 00:44:51 · 3 answers · asked by Pwincess FaFa 1

2007-09-23 00:13:43 · 3 answers · asked by roger federer rocks 1

As you know, a ring laser can measure rotation speed when it rotates around own axis (perpendicular to own's plane).
This kind of device can detect rotation speed of the Earth. But, for measure this speed, this device is placed paralel to the ground, (please see this pages:
http://www.ringlaser.org.nz/content/about_us.php
http://www.ringlaser.org.nz/content/gross_ring_facility.php)
Why the ring laser is paralel to the ground, when is suppose to be perpendicular to Earth's rotation axis when measure rotation of the Earth? What should measure then a ring laser when is positioned perpendicular to Earth's rotation axis?

2007-09-22 23:30:46 · 3 answers · asked by AFA 1

2007-09-22 22:52:35 · 13 answers · asked by SHAW M 1

2007-09-22 22:17:04 · 2 answers · asked by Haider 1

Something to do with the electricity supply or the mobile phone system perhaps. I can feel it in my nervous system...

This is a serious question. Thanks :-)

2007-09-22 21:52:34 · 8 answers · asked by 2kool4u 5

I am doing a physics lab and included are these two questions but I'm not positive I've done my calculations correctly.

First question is: If a 2.50kg physics book is dropped from rest at a height of 1.50m, how much time would it take the book to hit the ground? Assume no air resistance.

Second question is: If a 2.50kg physics book is dropped with an initial velocity of 10.0m/s from a height of 1.50m, how much time would it take the book to hit the ground. Assume no air resistance.

My calculated answer for the first questions was .55 seconds and for the second question .16 seconds.

If anyone can work these and let me know if I've done this correctly I would appreciate it very much. If my answers are in fact incorrect if you can put down your calculations that would be a big help so I can see what I am doing wrong.

Thanks to anyone who can help.

2007-09-22 20:43:48 · 2 answers · asked by doubtful 2

The fact that the spelling is far from phonetic - the same combinations of letters can stand for totally different words, like the "ough" in "tough", "though", "drought", etc.

2007-09-22 20:26:18 · 8 answers · asked by Anonymous

Define these two and diffrentiate.

2007-09-22 18:50:58 · 5 answers · asked by usman z 1

2007-09-22 17:33:07 · 1 answers · asked by areallthenamestaken 4

Stephanie hits a volleyball from a height of 0.80 m and gives it an inital velocity of +7.5m/s straight up.

A. How high wil the volleyball go?
B. how long will it take the ball to reach its maximum height?(hint: at maximum height, v=0m/s.

2007-09-22 17:03:51 · 1 answers · asked by Anonymous

In the case where the solid is not soluble in the liquid.

2007-09-22 16:46:59 · 3 answers · asked by Anonymous

2007-09-22 16:45:43 · 9 answers · asked by Anonymous