Physics - October 2007

Planet X has an equatorial radius of 7.70E7 m and a mass of 6.10E26 kg.
(a)Compute the acceleration of gravity at the equator of Planet X.
(b) What it the ratio of a person's weight on Planet X to that on Earth?

2007-10-10 11:43:55 · 1 answers · asked by tommy t 1

If a 20kg sled is being pulled across a horizontal surface at a constant velocity. The pulling force has a magnitud of 80N and is directed at an angle of 30 degrees above the horizontal.

2007-10-10 11:34:27 · 2 answers · asked by betty 1

How much force in newtons is used to break an egg on the edge?

2007-10-10 11:23:12 · 3 answers · asked by Anonymous

An astronaut on the Moon fires a projectile from a launcher on a level surface so as to get the maximum range. If the launcher gives the projectile a muzzle velocity of 26 m/s, what is the range of the projectile? [Hint: The acceleration due to gravity on the Moon is only one sixth of that on the Earth.]

2007-10-10 11:14:37 · 2 answers · asked by Anonymous

Hey Please help me with this question... i think they fall at same time...

if a bus and apple are dropped from same height which hits ground first? explain

2007-10-10 11:04:40 · 6 answers · asked by mbmimomf 1

A trough is 5 feet long and 1 foot high. The vertical cross-section of the trough parallel to an end is shaped like the graph of y=x^4 from x=−1 to x=1 . The trough is full of water. Find the amount of work in foot-pounds required to empty the trough by pumping the water over the top. Note: The weight of water is 62 pounds per cubic foot.

2007-10-10 10:54:50 · 1 answers · asked by mjs3382 1

The fastest recorded pitch in Major League Baseball, thrown by Nolan Ryan in 1974, was clocked at 162.3 km/h (100.8 mi/h). If a pitch were thrown horizontally with this velocity, how far would the ball fall vertically by the time it reached home plate, 18.3 m (60.0 ft) away?
m

2007-10-10 10:49:57 · 2 answers · asked by Anonymous

A daredevil jumps a canyon 13 m wide. To do so, he drives a car up a 14° incline.
(a) What minimum speed must he achieve to clear the canyon?
m/s
(b) If the daredevil jumps at this minimum speed, what will his speed be when he reaches the other side?
m/s

2007-10-10 10:48:55 · 1 answers · asked by Anonymous

You and your friends push a 74-kg greased pig up an aluminum slide at the
county fair, starting from the low end of the slide. The coefficient of
kinetic friction between the pig and the slide is 0.070.

(a) All of you pushing together (parallel to the incline) manage to accelerate
the pig from rest at the constant rate of 4.2 m/s2 over a distance of 1.5 m,
at which point you release the pig. The pig continues up the slide, reaching a
maximum vertical height above its release point of 45 cm. What is the angle of
inclination of the slide?
°


(b) At the maximum height the pig turns around and begins to slip down once
slide, how fast is it moving when it arrives at the low end of the slide?
m/s

2007-10-10 10:47:29 · 4 answers · asked by NiCkDlAyDsMaN 2

A box slides down a 26.2degree ramp with an
acceleration of 1.07 m/s/s.
The acceleration of gravity is 9.8 m/s/s.
Determine the coefficient of kinetic friction
between the box and the ramp.

2007-10-10 10:42:21 · 1 answers · asked by lilprincess_2good4u 1

I cant find the answer in my text book for some reason... I will choose best answer.

2007-10-10 10:37:00 · 1 answers · asked by zachmebay 2

At the beginning of a new school term, a
student moves a box of books by attaching a
rope to the box and pulling with a force of
F = 82.4 N at an angle of 63degrees.
The acceleration of gravity is 9.8 m/s/s.
The box of books has a mass of 14 kg and
the coefficient of kinetic friction between the
bottom of the box and the floor is 0.23.

What is the acceleration of the box? An-
swer in units of m/s/s.

2007-10-10 10:36:35 · 3 answers · asked by lilprincess_2good4u 1

Can anyone describe what 2-dimensional time would "look" like or "feel" like?
Are there any science fiction stories that you can reccommend that give a good visualization of 2 (or more) dimensions of time?
Some theories in physics, like string theory, use more than 3 dimensions of space. Are there any theories that use more than one dimension of time?

2007-10-10 10:34:00 · 1 answers · asked by Jeffrey K 7

Consider the 671 N weight held by two cables. The left-hand cable had tension T2 and makes an angle of theta2 with the ceiling. The right-hand cable had tension 450 N and
makes an angle of 50degrees with the ceiling.
The right-hand cable makes an angle of 50degrees
with the ceiling and has a tension of 450 N:

a) What is the tension T2 in the left-hand
cable slanted at an angle of theta2 with respect to
the wall? Answer in units of N.

b) What is the angle theta2 which the left-hand
cable makes with respect to the ceiling? An-
swer in units of degrees.

2007-10-10 10:30:53 · 1 answers · asked by lilprincess_2good4u 1

A ball falls from the top of a roof and its initial speed is 20m/s and the acceleration of gravity is 9.8m/s^2. How do I find how long it takes the first ball to hit the ground?

2007-10-10 09:37:44 · 1 answers · asked by KE 1

A rocket blasts off from rest and attains a speed of 45 in 15s. The astranaut has a mass of 57kg.

2007-10-10 09:33:37 · 1 answers · asked by betty 1

A truck driver with an initial speed of 30m/s spots an armadillo in the road ahead and begins to brake at a rate of 2 m/s^2 for 10 seconds. how far does her truck travel?

2007-10-10 09:28:37 · 1 answers · asked by qt123 1

The height of a helicopter above the ground is given by h = 3.00t^3, where h is in meters and t is in seconds. After 2.00 s, the helicopter releases a small mailbag. How long after its release does the mailbag reach the ground?

the answer in the book is 7.96 seconds, but can someone explain how to get that?

2007-10-10 09:26:36 · 2 answers · asked by Anonymous

A spring with k = 10.0 N/m is at the base of a frictionless 30.0° inclined plane. A 0.50 kg object is pressed against the spring, compressing it 0.1 m from its equilibrium position. The object is then released. If the object is not attached to the spring, how far up the incline does it travel before coming to rest and then sliding back down?
____m

2007-10-10 09:16:13 · 2 answers · asked by Anonymous

a pulley system is used to support and lift a 600 neuton weight. a person pulls on the rope

a) Calculate the force needed to support the mass in the air

b) Explain and calculate the work done to lift the weight through 1 meter.

2007-10-10 08:53:05 · 1 answers · asked by Anonymous

2007-10-10 08:52:22 · 3 answers · asked by Brittney J 1

2007-10-10 08:43:45 · 1 answers · asked by Maria V 1

A block is given an initial velocity of 2.00 m/s up a frictionless 22.0° incline. How far up the incline does the block slide before coming (momentarily) to rest?


Im sure this is most likely a very simple problem, however I just dont even know where to start! Thanks in advance!

2007-10-10 08:36:56 · 3 answers · asked by Anonymous

a) 0.1 seconds
b) 1 second
c) 10 seconds
d) 20 seconds
e) more than 20 seconds

2007-10-10 08:16:04 · 6 answers · asked by isabel l 1

a)nearly as fast as the waves it produce
b)as fast as the waves it produces
c)faster than the waves it produces

2007-10-10 08:05:17 · 1 answers · asked by isabel l 1

A 1100 N crate is being pushed across a level floor at a constant speed by a force of 300 N at an angle of 20.0° below the horizontal, as shown in Figure P4.37a.
(a) What is the coefficient of kinetic friction between the crate and the floor?
(b) If the 300 N force is instead pulling the block at an angle of 20.0° above the horizontal as shown in Figure P4.37b, what will be the acceleration of the crate? Assume that the coefficient of friction is the same as that found in (a).

2007-10-10 07:49:48 · 1 answers · asked by Anonymous

A sled weighing 61.0 N is pulled horizontally across snow so that the coefficient of kinetic friction between sled and snow is 0.100. A penguin weighing 73.0 N rides on the sled, as in Fig. P4.76. If the coefficient of static friction between penguin and sled is 0.700, find the maximum horizontal force that can be exerted on the sled before the penguin begins to slide off.

2007-10-10 07:47:15 · 1 answers · asked by swimchic632 2

An object initially at rest falls a distance h. use the formula y= - 1/2 gt^2 to express the time (t) it takes to fall in terms of h and g.

If the object is not initially at rest, but is moving horizontally with a speed v it will go a distance x-vt during the fall. use the time from part 1 to solve for v in terms of h, g, and x.

a balls is shot horizontally. its initially 1 m above ground. it hits the ground after traveling 2 m horizontally. what was the balls initial horizontal speed?

the ball is shot at an angle (theta) above horizontal. it is initially at ground level.. the distance it will travel before returning to the ground is x= v^2 sin (2 theta)/g. use the speed v of earlier ? and find the distance it will travel if (theta) = 30 degrees.

Given the range is x=v^2 sin (2theta)/g what angle should the ball be **** in order for it to travel the longest distance.

please show calculations! do any of the problems you can!

2007-10-10 07:47:01 · 1 answers · asked by Jamie 3

I have 2 questions.

1.) The light intensity on a screen behind a double slit is shown, in which y = 1.7 cm. The slit spacing is 0.20 mm and the wavelength of the light is 570 nm. What is the distance from the slits to the screen?

The graph peaks in the middle at 12 mW/m^2 and is 0 at each end.

2.) In a double-slit experiment, the slit separation is 195 times the wavelength of the light. What is the angular separation between two adjacent bright fringes?

I have no clue what to do. If anyone can help thanks.

2007-10-10 07:46:04 · 2 answers · asked by johnsonbuckeyefan 1

The drawing shows a circus clown who weighs 960 N. The coefficient of static friction between the clown's feet and the ground is 0.45. He pulls vertically downward on a rope that passes around three pulleys and is tied around his feet. What is the minimum pulling force that the clown must exert to yank his feet out from under himself?
Drawing: http://images.google.com/imgres?imgurl=http://webassign.net/CJ/04_58.gif&imgrefurl=http://www.webassign.net/v4cgi/student.pl%3FWebAssignUsername%3Ddemo%26WebAssignInstitution%3Ddemo%26WebAssignPassword%3Ddemo%26Department%3Dv4demo%26course%3D11,1%26struct%3DABDiAYAxBxBvEAEvBMDFDMCXAkCfEnBUAeDUEIDBBcAEAaERCEATAkEjDqCaBGEFBoELArCQDHCmAtCXBFDRBhCxuUCPEPDiDcAbBgEMEmCjDtErCXDkDh&h=321&w=225&sz=12&hl=en&start=1&um=1&tbnid=k3sQw_VDwFG1qM:&tbnh=118&tbnw=83&prev=/images%3Fq%3Dphysics%2BThe%2Bdrawing%2Bshows%2Ba%2Bcircus%2Bclown%2Bwho%2Bweighs%2B.%2BThe%2Bcoefficient%2Bof%2Bstatic%2Bfriction%2Bbetween%2Bthe%2Bclown%2527s%2Bfeet%2Band%2Bthe%2Bground%2Bis%2B.%2BHe%2Bpulls%2Bvertically%2Bdownward%2Bon%2Ba%2Brope%2Bthat%2Bpasses%2Baround%2Bthree%2Bpulleys%2Band%2Bis%2Btied%2Baround%2Bhis%2Bfeet.%2BWhat%2Bis%2Bthe%2Bminimum%2Bpulling%2Bforce%2Bthat%2Bthe%2Bclown%2Bmust%2Bexert%2Bto%2Byank%2Bhis%2Bfeet%2Bout%2Bfrom%2Bunder%2Bhimself%253F%26svnum%3D10%26um%3D1%26hl%3Den%26safe%3Doff%26rls%3DDKUS,DKUS:2006-32,DKUS:en%26sa%3DN

2007-10-10 07:35:04 · 2 answers · asked by Jim E 1