Free homework help here

can anyone tell/show me how to do this....

v2=x2+2ad
solve for d
im aware the anwser wont be a number ><

 

The 2 underneath, I'm assuming that's a square because the formula looks like the physics one with velocity final, initial, acceleration, and distance.

d = (V^2 - X^2)/2a

 

V^2 - x^2 = 2ad
(V^2 - x^2)/2a = d

Is that ok?

 

are you guys good at physics here?

 

I'm pretty good at it, what's the problem?

 

i have no problem atm, just when i do my hw i get stuck a lot so i might later next week

 

v^(2)=x^(2)+2ad

Since d is on the right-hand side of the equation, switch the sides so it is on the left-hand side of the equation.
x^(2)+2ad=v^(2)

Since x^(2) does not contain the variable to solve for, move it to the right-hand side of the equation by subtracting x^(2) from both sides.
2ad=-x^(2)+v^(2)

Divide each term in the equation by 2a.
d=(-x^(2)+v^(2))/(2a)

 

Anyone want to help me with some trig?

2sec(squared) x - 3 + tanx = 0

 

2sec?

what does that mean.

once i know that i can help.

 

Use your Trig Identities:
sec²x = 1 + tan²x

Therefore, you have:
2(1 + tan²x) - 3 + tanx = 0
2 + 2tan²x - 3 + tanx = 0
2tan²x + tanx - 1 = 0

^ Notice something? ^
Factor it. =D

(2tan - 1)(tan + 1)

^ Set both above equal to "0" ^

2tan - 1 = 0
2tan = 1
tan = 1/2

tan + 1 = 0
tan = -1

So, now you have (tan = 1/2) and (tan = -1)

Using a Unit Circle, find where Tangent is equal to 1/2 and -1. Or, use Tan Inverse of the numbers.

For (tan = 1/2), you will get 116.565 and 296.525, for Tangent is negative in Quadrants 2 and 4.

For (tan = -1), you will get 135 and 135, for Tangent is negative in Quadrants 2 and 4.

~~~~~~~~~~~~~~~~~~~~

If these are supposed to be in Quadrants 1 and 3, where Tangent is positive, I would be confused. Nevertheless, there you are Datsyuk4242, and good luck on your upcoming Tests / Quizzes as well!

 

I have a few physics questions and they have got me stuffed. if someone could help and justify there answer thanks

1) A spaceship travels with a speed of 0.7c as it passes the earth on its way to a distant star. The pilot of the spaceship measures the length of the moving ship as 30m

Determine its length as measured by a person on earth. Answer units in m.

2) (Extension of question 1) - The pilot of the spaceship observes that the spaceship travels for 9 years.

Determine how much time has passed according to a person on earth. Answer in units of years

3) (extension of question 1 & 2) Some time after the passing of earth, the pilot shoots a laser pulse backwards at a speed of 3*10^8 m/s (3 times 10 to the power of 8 meters per second) with respect to the spaceship.

Determine the speed of the laser pulse as measured by a person on earth. Answer in units m/s





Thanks Very Much

 

0.7c = v = 210000000ms^-1
l = 30m

l' = l[root(1-(v^2/c^2)]
l' = 30[root(1-(210000000^2/300000000^2)]
l' = 15.3m

I think this is right.

Too tired to do the other two, might do them tomorrow.

 

Thanks, i will see if it is. its actually due tonight

 

the answer isnt 15.3

 

I didn't root 0.51, so it should be 21.424m (5sf) according to my calculation then.

9/root[0.51] = 12.6025 years.

Right?

 

Yes and yes. well done. can't help with the thid question?

 

Some more questions are

~Energy is released during a nuclear reaction due to a conservation between mass and energy. Mass is not onserved. The inital and final amounts are different. If atotal of 19g of mass were "missing", how much energy is released? Answer in units of J (jules)


~A passanger on an interplanertay express bus traveling at 0.19c takes 6 miutes slee by his watch. How long would you measure the passangers sleep to be. Answer in units of minutes

~Assume 11g of a substance marked as "pure energy" is annihilate by 11g of a second substance "anti pure energy", How long would the energy released power a city which uses 2*10&9 W of power? Answer in units of hours

~ A protons rest mass is 1.67*10^-27 (1.67 times 10 to the negative 27). Calculate its total energy if it is accelerated to a speed of 0.75c. Answer in units of J

 

Can someone help me on my research paper?

I need to write 8-11 pages (double spaced) about the life of a white male abolitionist (anti-slavery guy) during the antebellum period (1840's)

anybody got any clue how in-depth it should be, and what I should write on each page? I have 6 primary sources, so that should help but I really don't feel like putting time in this (plus, this is a rough draft)

thanks for reading,
chant

 

I can't figure this out-

Tell whether the events are independent or dependent.

You randomly choose a utensil from a drawer with 11 spoons, 6 forks, and 7 knives. Without replacing the first item, you draw another.
Event A: You draw a spoon first.
Event B: You draw a fork second.

The events are:


---------------------------------------------------------------------------------------

 

Event B is dependent on event A, I believe. This is because if you draw something without replacing it, you affect the probability of drawing a second item of a certain type (since you've reduced the total number of items you're choosing things from by 1).