Physics - October 2007

In science class, my teacher told us that nuclear fusion in the sun occurred in the core. He said, "Nuclear fusion in the case of the sun is when two hydrogen protons smash together to create deuterium, which has one neutron. Then the deuterium atom smashes together with another hydrogen proton to make Helium-3. Then two Helium-3 smash together to make a Helium-4."

First, is this correct?
Second, can nuclear fusion in the sun still occur with a hydrogen proton and a hydrogen neutron? Will it emit as much energy?


Please keep in mind that I'm an eighth grader, and that the explanation was for eighth graders to comprehend.

2007-10-07 10:57:01 · 4 answers · asked by Anonymous

and why arent we feeling sick and dizzy and keep falling over being drunk doesnt count

2007-10-07 10:41:51 · 20 answers · asked by flowersinthewind 5

A generator rotating at 100rpm makes 1.24V. What will the output be at 250rpm? I can't seem to use any of my equations to figure this out. Which one do you use?

2007-10-07 10:14:19 · 1 answers · asked by Stumped 1

a flute open at both ends and an organ pipe closed at one end have the same length
organ pipe has a fundamental frequency of 130hz
what is the flutes fundamental frequency and what assumptions are we making

2007-10-07 09:57:56 · 1 answers · asked by Anonymous

A curve of radius 155 m is banked at an angle of 24°. At what speed can it be negotiated under icy conditions where friction is negligible?

I think I can get it but i dont know how i am going to use just angle and radius to solve this. I need to somehow get the force to get velocity but i dont have mass. Help?

2007-10-07 09:39:45 · 1 answers · asked by Anonymous

You find yourself on a strange planet, and have rigged a setup with a launcher that is 5 meters off the ground, and the launcher will shoot a projectile with an initial velocity of exactly 4.0 m/s. The projectile travels 4.5 m along the ground. From this, you conclude that free-fall gravitational acceleration on this planet is _______ m/s^2.

The answer is supposed to be 7.9 m/s^2.

When I was finding all of the x and y values, this is what I came up with:

X-direction: displacement = 4.5 m
acceleration: 0 m/s^2
initial & final veloctiy: 2.97 m/s
time: 1.51 seconds

Y-direction: displacement: -5 meters
Initial velocity: -2.67 m/s
time: 1.51 seconds.

I guess its possible that I keep messing up the algebra when trying to find the free fall acceleration, but I think its more likely that I came up with one or more incorrect values for the known information (particularly the inital velocities). I'd greatly appreciate it if someone could enlighten to as to where I'm going wrong.Thanks.

2007-10-07 09:33:08 · 1 answers · asked by Anonymous

A bicycle tire rolls without slipping along the ground with its center of mass moving with speed v . You may neglect any rolling resistance. What is the speed with respect to the ground of each of the following 4 points on the wheel?
a) at the top of the wheel
b) at the 3 o'clock position of the wheel
c) at the 9 o'clock position of the wheel

so i've been trying to figure this problem out for a while and i'm not sure how to go about it. there's a tangential velocity (v) at every one of these points but how do you take angular acceleration into account in this case? how do you figure out which direction the speed at each of the points takes?

2007-10-07 09:03:40 · 3 answers · asked by Anonymous

What would the affect be of our atoms being bigger that the same atoms of a smaller universe?

2007-10-07 08:59:12 · 2 answers · asked by Mr. Bodhisattva 6

The question reads:

A roof truss is made of two rafters, and a tie beam. Each end of the tie beam is supported by a wooden post. If a 100kg mass is suspended from the rafters, as shown, determine:

a.) The compression in each post
b.) The compression in each rafter
c.) The tension in each tie beam

So the diagram is an isoceles triangle sitting on two posts. The length of the base of the triangle is 12.0m, and the 100kg mass is hung from the top of the triangle.

I got the force of gravity on the mass (981N [Down]), and the length of each rafter (6.5m) and their angle to the 12.0m base (25* each).

But I don't know what to do from there.

2007-10-07 08:55:43 · 1 answers · asked by Anonymous

the qusetions are as follows:
A car moving westward along a straight, level road increases its velocity uniformly from 24 m/s to 25 m/s in 10 s.
(a) What is the car's acceleration?
m/s2 (westward)
(b) What is its average velocity?
m/s (westward)
(c) How far did it move while accelerating?
m


I thought to figure this problem out I would have to take the final velocity (25m/s) minus the original velocity (24 m/s) diveded by the time (10 s). which would give me .1 m/s/s (.1 m/s^2) . But, this stupid webassign homework is kicking my ***.

2007-10-07 08:32:36 · 2 answers · asked by Anonymous

in a boiler hot water from the boiler rise and flows into the tank where it rises to teh top. when you use a hot water tap at home, you draw off hot water from teh top of the tank. what would happen if we connected the hot taps to the bottom of the tank? plz reply in convectional terms! thankyu :)

2007-10-07 08:29:20 · 1 answers · asked by Anonymous

I have an experiment in which I have to calculate the time it takes for a weight to falls a certain distance and I would like to know what the type of sensor I could use.

Due to the procedure of the experiment I need the sensor to detect a particular part of the weight and for this reason an object( i dont know what) could be attached to the weight. Could I use an infra red sensor that measures the temperature of this specific object which is attached to the weight?

If not what else?

Thank You

2007-10-07 08:11:20 · 3 answers · asked by Anonymous

I am really confused on this question. Could someone please assist me? Thank you!

An Olympic skier moving at 11 m/s down a 18 degree slope encounters a region of wet snow of coefficient of kinetic friction of mu = .36. The acceleration of gravity is 9.8 m/s^2. How far down the slope does she travel before coming to a halt? Answer in units of m.

2007-10-07 07:38:52 · 1 answers · asked by sg88 1

Assume you are a medieval knight attacking a castle with a cannon. The ball leaves the cannon with a speed of 49.3 m/s. The barrel's angle with respect to the ground is 44.5 degrees, and you make a perfect hit on the tyrant's chamber which is at the same level as the cannon's muzzle (H=0 m). What is the time of flight of the cannon ball?

2007-10-07 07:36:01 · 2 answers · asked by Anonymous

A man decides to climb an office tower using the stairs. If the floors are 3.8 m apart, how much gravitational potential energy would the man have relative to the ground floor if he made it to the fifth floor?

The answer is 41 J, but how would you figure that out without knowing the mass?

2007-10-07 07:24:19 · 1 answers · asked by Anonymous

2007-10-07 07:20:26 · 11 answers · asked by strongbow 3

2007-10-07 07:12:00 · 7 answers · asked by cindy d 4

a 60 watt filament lamp is operated from an alternating current supply. The RMs voltage of the supply is 240v at a frequency of 50 hz

(i) calculate the maximum current in the filament?

(ii) and show that the maximum power dissipated in the lamp is 120 w

Thanks!

2007-10-07 06:57:47 · 1 answers · asked by NKS 2

2007-10-07 06:56:42 · 4 answers · asked by Anonymous

How can i speed up the time a little bit, just to make 2 years pass in 2 seconds.

2007-10-07 05:45:37 · 6 answers · asked by fast&furious 2

A ball thrown horizontally at 25 m/s travels a horizontal distance of 50 m before hitting the ground. From what height was the ball thrown?
m

2007-10-07 05:29:48 · 8 answers · asked by lol83388 1

A boat takes 2 hours to travel 30 km down a river, then 7.5 hours to return. How fast is the river flowing?
wrong check mark km/hr

2007-10-07 05:29:17 · 7 answers · asked by lol83388 1

As a science fair project, you want to launch an 600 g model rocket straight up and hit a horizontally moving target as it passes 35 m above the launch point. The rocket engine provides a constant thrust of 15.0 N. The target is approaching at a speed of 15 m/s. At what horizontal distance between the target and the rocket should you launch?

2007-10-07 05:26:57 · 3 answers · asked by Jim E 1

Sam (75 kg) takes off (from rest) up a 50 m high, 10° frictionless slope on his jet-powered skis. The skis have a thrust of 240 N. He keeps his skis tilted at 10° after becoming airborne, as shown in Figure P6.43. How far does Sam land from the base of the cliff?

2007-10-07 05:26:01 · 1 answers · asked by Jim E 1

Susan, driving north at 55 mph, and Shawn, driving east at 45 mph, are approaching an intersection. What is Shawn's speed relative to Susan's reference frame?

2007-10-07 05:24:53 · 1 answers · asked by Jim E 1

for every force there is an equal and opposite force. i understand that. but what if there is a big metal box and it gets place on top of quicksand? what exactly happends there? is it that as it sinks the metal box still puts an equal and opposite force on the quick sand, although its sinking...wait..that woundlt make sense...im confused...

2007-10-07 05:04:33 · 5 answers · asked by silyrabbittwixR4kidz 3

The drawing shows a circus clown who weighs 850 N. The coefficient of static friction between the clown's feet and the ground is 0.40. 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?

2007-10-07 04:49:06 · 1 answers · asked by Anonymous

Sam (85 kg) takes off (from rest) up a 50 m high, 10° frictionless slope on his jet-powered skis. The skis have a thrust of 160 N. He keeps his skis tilted at 10° after becoming airborne. How far does Sam land from the base of the cliff?

2007-10-07 04:47:52 · 2 answers · asked by Anonymous

An object is initially at rest moved & attains a uniform acceleration covering a distance of 7.4m in 2.5 sec. What is the acceleration of the object?

2007-10-07 04:05:09 · 4 answers · asked by Mumu [Neji] XD 1

2007-10-07 04:02:17 · 2 answers · asked by Anonymous