# Posts by Raf

Total # Posts: 75

**Computer**

what is a computer?

*February 3, 2013*

**Travel tourism**

describe tourism

*February 2, 2013*

**Computer**

Write a pseudocode to input 10 temperatures per day for 20 days and output the average per day and the average for the 20 days.

*February 2, 2013*

**Computer Studies**

Write a pseudocode to input 10 temperatures per day for 20 days and output the average per day and average for the 20 days.

*January 30, 2013*

**Linear Algebra**

4 points A,B,C and D are situated in a 3-dimensional space. In a certain spot, the coordinates of A, C and D are known: A(1,1,1) C(2,0,1) D(0,3,0) The coordinates of the barycentre of {A,B,C} are: (4/3, 1/3, 4/3). a) Determine the coordinates of point B in the used spot.

*May 1, 2012*

**Linear Algebra**

4 points A,B,C and D are situated in a 3-dimensional space. In a certain spot, the coordinates of A, C and D are known: A(1,1,1) C(2,0,1) D(0,3,0) The coordinates of the barycentre of {A,B,C} are: (4/3, 1/3, 4/3). a) Determine the coordinates of point B in the used spot.

*April 30, 2012*

**Physics(2)**

A crane is holding a bloc of metal of 10 000kg. If the crane's arm weights 1000kg and is 10,0m long, what is the tension in cable a and how big is the force exerted on the pivot of the cranes arm. the cable passes through the top of the cranes arm and then is vertical ...

*February 22, 2012*

**Physics - Question**

thanks bob!

*February 22, 2012*

**Physics - Question**

I have this number where they give me the coordinates of 3 particles and the mass of each one of them. Afterwards, there's a force applied on 2 of those particles and they ask me to calculate the systems total moment of inertia. But then they ask me this: If the system ...

*February 22, 2012*

**Calculus AB**

tnx for the correction Steve, my bad Sarah

*February 21, 2012*

**Calculus AB**

What you do with ln(xy) is just separate it into 2 pieces: ln(x) + ln(y) ln(x) + ln(y) = 1 + y' 1/x + y'/y = 1 + y' 1/x - 1 = y' (1 - y)

*February 21, 2012*

**Physics**

you have: m1 = 60 kg v1 = 5 m/s m2 = 40 kg v2 = 0 m/s (I presume she's not moving because there's no mention of her velocity) so m1v1 = (m1 + m2)V V = m1v1 / (m1 + m2) solve for v once you find v, you plug it into your kinetic energy formula: K = 1/2mv^2 where you'...

*February 21, 2012*

**algebra**

Rise is the change in the y coordinate, if you think of the graph, you are going up or down. Run is the change in the x coordinate, left to right. To find the change, we take the second coordinate, and subtract the first coordinate. So, what does that give us? y2 - (y1) = y ...

*February 21, 2012*

**french**

il/elle acheter will be il/elle VA acheter je acheterai will be written j'acheterai

*February 21, 2012*

**Physics**

Kinetic energy is defined with K = 1/2*m*v^2 so you have Kf - Ki [1/2(m)(vf)^2] - [1/2(m)(vi)^2] = m = mass v = velocity; f for final, i for initial your answer will be in kg * m/s^2 which is the developed way of writing Newtons because 1 kg * m/s^2 = 1 N

*February 21, 2012*

**statistics**

the science that deals with the collection, classification, analysis, and interpretation of numerical facts or data, and that, by use of mathematical theories of probability, imposes order and regularity on aggregates of more or less disparate elements.

*February 21, 2012*

**physics/chemistry**

same goes for salts

*February 21, 2012*

**physics/chemistry**

Electrical conductivity is a physical property. A chemical property involves a change that occurs. However, when electricity passes through an object or substance, no change occurs.

*February 21, 2012*

**Physics (2)**

I have this number where they give me the coordinates of 3 particles and the mass of each one of them. Afterwards, there's a force applied on 2 of those particles and they ask me to calculate the systems total moment of inertia. But then they ask me this: If the system ...

*February 21, 2012*

**Physics**

A crane is holding a bloc of metal of 10 000kg. If the crane's arm weights 1000kg and is 10,0m long, what is the tension in cable a and how big is the force exerted on the pivot of the cranes arm. the cable passes through the top of the cranes arm and then is vertical ...

*February 21, 2012*

**Physics**

A crane is holding a bloc of metal of 10 000kg. If the crane's arm weights 1000kg and is 10,0m long, what is the tension in cable a and how big is the force exerted on the pivot of the cranes arm. the cable passes through the top of the cranes arm and then is vertical ...

*February 20, 2012*

**Physics**

I can't figure this problem out: A bar that's initially held horizontally, weights 500g and is 2m. long. It's maintained by a pivot at its extremity. We then let it fall until it's vertical. We neglect air resistance. What will be the angular velocity at that ...

*February 17, 2012*

**physics**

thank you

*February 8, 2012*

**physics**

If I have a unit vector of (2.06 j)m/s(I have no i vector because it's 0 on a horizontal impulsion, in accordance with my problem,how do I convert that into polar notation? Will I be doing rcos0, with r being 2.06? . But then again I have no angle, just the angle of before...

*February 8, 2012*

**Physics - Question**

but the angle will still have no effect right?

*February 7, 2012*

**Physics - Question**

thank you very much!

*February 7, 2012*

**Physics - Question**

A ball of 250g hits the floor at a velocity of 2,50 m/s at an angle of 70* relative to the vertical. The vertical force in function with time between the floor and the ball is: from 0 to 50 N : from 0 to 1 sec. from 50 N to 100 N : from 1 to 2 sec. constant 100 N : from 2 to 3...

*February 7, 2012*

**physics**

I know that I have to use 1/2 mv^2 for the velocity and mgh for gravitational energy, but I'm lost from here, especially when they ask to put it in unit vectors. Thank you

*February 6, 2012*

**physics**

A ball of 250g hits the floor at a velocity of 2,50 m/s at an angle of 70* relative to the vertical. The vertical force in function with time between the floor and the ball is: from 0 to 50 N : from 0 to 1 sec. from 50 N to 100 N : from 1 to 2 sec. constant 100 N : from 2 to 3...

*February 6, 2012*

**Physics - Question**

When I'm asked to find work done by air resistance against a skier on a slope, will I have to do: Wr = -Fr*d or is it affected by an angle: Wr = -Fr*d*cosTHETA I was thinking that it isn't because air resistance isn't a specific force acting at one spot but ...

*February 6, 2012*

**Physics - Verification**

oh and I see what you mean, it's 95 116 J, thanks again!

*February 6, 2012*

**Physics - Verification**

and drag and friction work has to be higher at the end than gravity in order to stop the skier at the bottom, right?

*February 6, 2012*

**Physics - Verification**

what is the mistake? And thank you for the information!

*February 6, 2012*

**Physics - Verification**

A skier (75 kg) goes down a 15* slope. The coefficient of kinetic friction between the skis and the snow is 0.185. The length of the slope is of 500m. a) What is the work done by gravity? Answer) Wmg = mgd = 75kg(9.8N/kg)500m(sin15) = 354 977 J Is it cos or sin? And is Work ...

*February 6, 2012*

**physics**

same thing with kinetic friction. I have a question where they ask me to find the work done by friction between the skis and the snow. my answer is: Wf = -Fc * d, but I have a feeling that I need to add the angle to it, or is that only with gravity?

*February 6, 2012*

**physics**

This is a theory question. Let's say I go down a slope on my skis. When I want to calculate the Work done by air resistance, do I take the angle of the slope in consideration? For example, will it be: Wr = -Fr * d * sinTHETA or will it only be Wr = -Fr * d Thank you

*February 6, 2012*

**pHysics**

A ball of 250g hits the floor at a velocity of 2,50 m/s at an angle of 70* relative to the vertical. The vertical force in function with time between the floor and the ball is: from 0 to 50 N : from 0 to 1 sec. from 50 N to 100 N : from 1 to 2 sec. constant 100 N : from 2 to 3...

*February 6, 2012*

**physics**

how do you find this? 1500*0+5000V=6500V' Thank you for your time

*February 5, 2012*

**physics**

A truck of 5000kg hits a car of 1500kg at an intersection. After the collision, both vehicles remained glued together and slid over a distance of 30 meters before coming to a halt. Knowing that the coefficient of kinetic friction between both vehicles and the street is 0.700, ...

*February 5, 2012*

**Physics**

A truck of 5000kg hits a car of 1500kg at an intersection. After the collision, both vehicles remained glued together and slid over a distance of 30 meters before coming to a halt. Knowing that the coefficient of kinetic friction between both vehicles and the street is 0.700, ...

*February 4, 2012*

**Physics - Verification**

okay cool, thanks a lot Bob

*February 3, 2012*

**Physics - Verification**

nevermind my first question, my mistake hehe

*February 3, 2012*

**Physics - Verification**

and why isn't it Wg = Wspring - Wfriction as friction is going to other way?

*February 3, 2012*

**Physics - Verification**

ohhh I see now, but when you say Work done on spring, you take the Energy formula which is 1/2 k x^2 , wouldn't the work on a spring be mu*N*x?

*February 3, 2012*

**Physics - Verification**

where Kf is = 0

*February 3, 2012*

**Physics - Verification**

made a mistake when I wrote Ef = Kf + Ugf instead it's --> Ef = Kf + Ugf + Usf

*February 3, 2012*

**Physics - Verification**

Hello, just wanted to verify is what I did is good. I posted this question yesterday and Bob helped me, so just wanted to be sure it's good. The problem is: A bloc of 10 kg is put at the top of an inclined plan of 45 degrees (to the left), attached to a spring which has a ...

*February 3, 2012*

**Physics**

Okay so from what I understand, I find the elongation from the total Work done on the spring and of course by isolating it in my equation. Sorry if my terms aren't good, I do it in french and try to translate it as good as possible

*February 2, 2012*

**Physics**

and what does mu stand for in x*mg*cosTheta*mu ? Thank you for your time!

*February 2, 2012*

**Physics**

is it always sinTheta for a force down a plane? Or does it depend on the inclination (left, right)

*February 2, 2012*

**Physics**

A bloc of 10 kg is put at the top of an inclined plan of 45 degrees (to the left), attached to a spring which has a spring constant of 250 N/m. The coefficient of kinetic friction between the bloc and the surface of the inclined plan is of 0,300. What is the maximum elongation...

*February 2, 2012*

**Physics**

A bloc of 10 kg is put at the top of an inclined plan of 45 degrees (to the left), attached to a spring which has a spring constant of 250 N/m. The coefficient of kinetic friction between the bloc and the surface of the inclined plan is of 0,300. What is the maximum elongation...

*February 1, 2012*

**Math**

I don't understand the question either, that's why I posted it here and that's exactly how the problem is written word by word, so I have really no idea :(. From what I can interpret, is that we're looking for what sum of two numbers m + n would give a minimal ...

*October 27, 2011*

**Math**

There are many pairs of numbers (positive and negative) of which the sum is worth the unit. Of those, find the 2 numbers whose sum, double the square of the first number and the square of the 2nd number would give a minimal value.

*October 27, 2011*

**Math**

There are many pairs of numbers (positive and negative) of which the sum is worth the unit. Of those, find the 2 numbers whose sum, double the square of the first number and the square of the 2nd number would give a minimal value.

*October 27, 2011*

**Math**

There are many pairs of numbers (positive and negative) of which the sum is worth the unit. Of those, find the 2 numbers whose sum, double the square of the first number and the square of the 2nd number would give a minimal value.

*October 27, 2011*

**Math2**

The universal law of gravitation determines the amount of force exerted by a constant mass (M) on another constant mass (m), separated by a distance (r), is given by the expression F = ( -GmM )/r^2 a) What mathematical expression characterises the instant rate of change of the...

*October 18, 2011*

**Physicss**

1. Carlos jogs in a straight line at a constant speed of 1.5 m/s. He passes by Victoria, who, 10 seconds after Carlos had passed her, starts accelerating at a constant rate of 0.50 m/s^2 a) How much time after the passing of Carlos does it take Victoria to catch up to him? b) ...

*October 18, 2011*

**Physics**

1. Carlos jogs in a straight line at a constant speed of 1.5 m/s. He passes by Victoria, who, 10 seconds after Carlos had passed her, starts accelerating at a constant rate of 0.50 m/s^2 a) How much time after the passing of Carlos does it take Victoria to catch up to him? b) ...

*October 17, 2011*

**Math**

tnx Steve! Cheers

*October 15, 2011*

**Math**

The universal law of gravitation determines the amount of force exerted by a constant mass (M) on another constant mass (m), separated by a distance (r), is given by the expression F = ( -GmM )/r^2 a) What mathematical expression characterises the instant rate of change of the...

*October 15, 2011*

**Math**

Evaluate: (without using Hopital's rule) d) lim (6-3x)/(((5x+6)^1/2)-4) x->2

*September 27, 2011*

**calculus**

the question didn't submit well, here's the problem: lim (6-3x)/(((5x+6)^1/2)-4) x->2

*September 26, 2011*

**calculus**

Evaluate: (without using Hopital's rule) d) lim (6-3x)/(((5x+6)^1/2)-4) x->2 ^ | square root

*September 26, 2011*

**physics**

a car brakes to a halt in 5 seconds. The position of the car versus time is given by: x = 10t - t^2 a) What is the average speed between 0 s. and 4 s.? Thank you

*September 21, 2011*

**MATH - Calculus**

and it's the factorization that I can't seem to come up with, thanks for your quick answer too

*September 12, 2011*

**MATH - Calculus**

yes I know, it is supposed to give 0/0 and they ask us to manipulate the limit algebraically in order to be able to factorize

*September 12, 2011*

**MATH - Calculus**

Evaluate the following limit: e) lim f(x)-f(a) / x - a x->a if f(x) = x^2 + 5

*September 12, 2011*

**MATH - Calculus (2)**

if lim f(x) = a^3 x->a and if lim g(x) = a^2 x->a calculate the following limit: lim f(x)*(x-a)/(x^3-a^3)*g(x) = x->a

*September 11, 2011*

**MATH - Calculus**

Evaluate the following limit: e) lim f(x)-f(a)/ x - a x-> a if f(x) = x^2 + 5

*September 11, 2011*

**math**

speed = km/h Car speed = 3 km/3hours = 1 km/1hour = 1 km/h

*September 11, 2011*

**science**

Calculate the solubility of silver chloride in 10.0 M ammonia given the following information: Ksp (AgCl) = 1.6 x 10^–10 Ag+ + NH3--->AgNH3+ K=2.1x10^3 AgNH3+ + NH3-----> Ag(NH3)2+ K=8.2x10^3 Answer : 0.48 M Calculate the concentration of NH3 in the final ...

*May 1, 2011*

**chemistry**

Calculate the solubility of AgCl in: Ksp = 1.6x10^-10 a) 100 ml of 4.00 x 10^-3 M Calcium chloride b) 100 ml of 4.00 x 10^-3 M Calcium Nitrate all i know is 1.6x10^-10=[Ag+][Cl-] which is 1.6x10^-10=x^2 x=1.3x10^-5, giving the M of Ag and Cl. Don't know how to go further

*May 1, 2011*

**chemistry**

Consider the equation A(aq) + 2B(aq) 3C(aq) + 2D(aq). In one experiment, 45.0 mL of 0.050 M A is mixed with 25.0 mL 0.100 M B. At equilibrium the concentration of C is 0.0410 M. Calculate K. a) 7.3 b) 0.34 c) 0.040 d) 0.14 e) none of these the answer for this is suppose to be ...

*April 4, 2011*

**operations management**

Can someone please post the answer for these questions?

*June 16, 2008*

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