Physics - November 2007

If suddenly loses its load and the mass were cut in HALF, what would be the car's momentum?

2007-11-15 12:30:29 · 2 answers · asked by kiwi 1

I'm stuck on the last 3 questions.... please help me thanks..do any question u know


1. Two 100 kg lead spheres are suspended from 100m long massless cables. The tops of the cables have been carefully anchored exactly 1m apart. What is the distance between the centers of the spheres.

2. A 1.0kg object is released from rest 500km ( approx. 300 miles) above the earth.
a.What is its impact speed as it hits the ground? Ignore air resistance.
b. What would the impact speed be if the earth were flat?
c. By what % is the flat-earth calculation in error.
d. Suppose a space shuttle astronaut, while out for a stroll, "drops" a 1.0kg hammer. Will it fall to earth? Explain why or why not.

3. 2 identical planets of mass M and radius R spaced 6R apart. Ignore the rotation of the planets about each other .What is the escape speed of a rocketlaunched from (a) point A(first planet) and (b) point B(the middle point between first planet and second?

2007-11-15 12:25:27 · 2 answers · asked by tmackun135 1

PHYSICS HELPERS I need your help on 3 word problems help?
PHYSICS HELPERS I need your help on 3 word problems help?
QUESTION !
Two towns, A and B, are 200 miles apart. Car 1 starts from town A and at the same time, car 2 starts from town B. They move towaRD each other with constant speeds: Car 1 at 50 mph, car 2 at 40mph.

A. How far apart are the two cars if car 2 has travel a time triangle t (change of t)

B. Where do the cars meet? If you use an equation intrpret the expression on each side and tell why you set them equal.


QUESTION 2

Two objects start at 30km apart at the same time and move toward each other with uniform motion. Object A has a speed of 6.3 km/h and object B has a speed of 4.5 km/h. When will they meet.


QUESTION 3
on a straight inclined track, a ball rolling uphill takes 1.3 seconds to slow down from a velocity of 135cm/s to a velocity of 65 cm/s. On the same track how much time would it take a rolling ball with velocity 85 cm/s to reach a velocity of 0? Explain your reasoning. Do not use algebra

2007-11-15 11:54:56 · 2 answers · asked by ? 1

PHYSICS HELP PLEASE!! grade 11, thank you?
on a level ice surface( coefficient of friction = 0.1) two boys stan facing each other 0.15m apart. one has a mass of 45kg and the other 65kg. the smaller boy pushes the bigger boy with a force of 55N for o.4s. At the en of the push how far apart will the boys be? THANK YOU

2007-11-15 11:26:57 · 2 answers · asked by arandjbar15 2

A child exerts a tangential 41.0 N force on the rim of a disk-shaped merry-go-round with a radius of 2.27 m. If the merry-go-round starts at rest and acquires an angular speed of 0.087 rev/s in 3.54 s, what is its mass?

Help please. I keep getting the wrong answer. Thanks!

2007-11-15 11:17:56 · 1 answers · asked by Tana 1

How much infrared radiation reaches the earth within 1 hour

2007-11-15 11:03:11 · 2 answers · asked by ? 3

I have no idea how to do this problem, so if you can walk me through step by step, it would be very much appreciated!

http://i231.photobucket.com/albums/ee10/mitochondria3/DavidGoliath.jpg

2007-11-15 11:02:03 · 2 answers · asked by Louee 3

How reflective is a solar semiconductor compared to a mirror when the mirror be at say 99% reflectivity?

2007-11-15 10:42:19 · 1 answers · asked by Ben 2

1)what may cause a ball to miss the target?
2)you probably noticed that the range of the ball increases in direct proportion to the speed at which it left the ramp. the speed depends on the release point of the ball on the ramp. what roles do you think air resistance had in this experiment?

3)should the height of the can be taken into account when measuring the vertical distances h?

2007-11-15 10:36:47 · 1 answers · asked by peipei91189 1

Can anyone explain space or time as entities within themselves? Are they not simply measures of 'how much?' What is the definition of space? What is the definition of time?

2007-11-15 10:32:16 · 10 answers · asked by Anonymous

The springs unstreched lenth is 52.3 cm, its k= 125 N/m and the mass = 612 g. You hold the mass on top of the spring until its at equilibrium.
A) Find the length the spring is compressed.
B) If you let the mass go and let it fall on its own whats the length of the spring then at the bottom.

Thanks in advance

2007-11-15 10:25:37 · 1 answers · asked by Need help plz!!! 1

A force of 40 N is required to pull a 10 Kg wooden block at a constant velocity across a smooth glass surface on Earth. What force would be required to pull the same wooden block across the same glass surface on the planet Jupiter?

How would you go about solving this problem? Help please.

2007-11-15 10:23:12 · 1 answers · asked by AxNxG 2

Current vacuum technology can achieve a pressure of
1.0 x 10^(-10) of Hg. At this pressure, and at a temperature of 30.0 degrees C, how many molecules are in 5.00 cm cubed ?

2007-11-15 10:22:53 · 1 answers · asked by gbutterfly339 1

A gun that shoots corks of mass 0.0045 kg uses a spring of spring constant 9.6 N/m. The b = 0.22 m long spring is compressed to a = 0.13 m. Its 0.22-m long barrel exerts a constant 0.26 N force of friction on the cork when the gun is fired. What is the cork’s speed in m/s at the muzzle of the gun?

2007-11-15 10:22:24 · 1 answers · asked by Anonymous

(This ride is a swing carousel)

An amusement parkride consists of a rotating circular platform 8.00m in diameter (radius = 4) from which 10 kg seats are suspended at the end of 2.50 m massless chains. When the system rotates, the chains make an angle (theta = 28.0 degrees) with the vertical.

here are the questions...

What is the speed of each child seat?
Find the tension in the chain when a 40 kg child sits in the seat (10kg + 40 kg)?

plz help

Thank you!

2007-11-15 10:11:41 · 1 answers · asked by Alex M 1

I know the period (T) of the object, the mass of the earth (obviously), the radius of earth, I can calculate the objects velocity but I do not know how to find the mass of the object. Thanks.

2007-11-15 09:56:30 · 1 answers · asked by Mark K 1

air at 300k and bulk velocity 8 m/s flows over a flat horizontal plate with a temperature of 1000k at all points on its surface. given that
nu=0.32PR(1/3)RE(1/2)(TA/TS)0.117
calculate the heat transfer rate form one side over the first 100mm and the first 200mm.

Ta is the bulk air temperature, and Ts is the surface tmperature . the fluid properties should be obtained at the mean temperature

2007-11-15 09:55:14 · 1 answers · asked by Anonymous

How reflective is a solar semiconductor compared to a mirror when the mirror be at say 99% reflectivity?

2007-11-15 09:41:55 · 1 answers · asked by Ben 2

on a level ice surface( coefficient of friction = 0.1) two boys stan facing each other 0.15m apart. one has a mass of 45kg and the other 65kg. the smaller boy pushes the bigger boy with a force of 55N for o.4s. At the en of the push how far apart will the boys be? THANK YOU

2007-11-15 09:28:38 · 1 answers · asked by arandjbar15 2

2007-11-15 09:11:13 · 3 answers · asked by Anonymous

2007-11-15 09:07:33 · 2 answers · asked by Anonymous

2007-11-15 09:02:51 · 2 answers · asked by baby_j 1

What is the wavelength (m) of a radio frequency is 162.5 MHz ??

2007-11-15 08:48:40 · 4 answers · asked by killakam2422 1

To pull a wagon across a lawn with constant velocity, you have to exert a steady force. Reconcile this fact with Newton's first law, which says that motion with constant velocity requires no force.

Please help!

2007-11-15 08:48:01 · 3 answers · asked by mooncutie256 1

Two balls, of masses mA = 36 g and mB = 76 g are suspended. The lighter ball is pulled away to a 60° angle with the vertical and released.

(a) What is the velocity of the lighter ball before impact? (Take the right to be positive.)
I got the answer to this and it is 1.71, what I can't figure out is the next questions.

(b) What is the velocity of each ball after the elastic collision?
(c) What will be the maximum height of each ball (above the collision point) after the elastic collision?

This is due soon, so any help is greatly appreciated.

2007-11-15 08:44:15 · 1 answers · asked by mookle_x 1

2007-11-15 08:38:51 · 3 answers · asked by pickneyjc 1

The activity of a sample drops by a factor of 10 in 8.0 minutes. What is its half-life?
_______________ min

2007-11-15 08:30:26 · 1 answers · asked by Jessie L 2

I need to write a 2 page paper on gravity (relating to physics)
can someone please help me out with this.... can someone direct me to some sites anything that will help me i really need help on this.... anyone know where i can get the whole paper from ..? Thanks in advanced ...

2007-11-15 08:03:52 · 1 answers · asked by Anonymous

A jet of water squirts out horizontally from a hole near the bottom of the tank. The water shoots out .546 m from the tank and the water tank is held on a pedastol that is 1.28 m above the ground. What is the speed of the water coming out of the hole?


The second part is The hole has a diameter of 3.63 mm. What is the height of the water level in the tank?

2007-11-15 07:50:09 · 1 answers · asked by jULIAN C 2

Hey there,
Can anyone please answer these questions:

(1) Is velocity on an incline constant or variable?
(So my graph should be a straight line or a curve?)

(2) Is acceleration on an incline constant or variable?
(So my graph should be a straight line or a curve?)

Thank you very much.

2007-11-15 06:32:04 · 5 answers · asked by Anonymous