Friday

October 28, 2016
Total # Posts: 122

**Math**

Draw a picture that represents 3*50=150

*March 29, 2016*

**math**

how many digits r there in 8 tens + 13 ones

*September 19, 2014*

**riddle **

Did you hear about . . . the words are something like away five ten music were who tigers a two cash got the store dough etc .

*November 22, 2011*

**4th grade math**

help me please

*November 16, 2010*

**Physics - work done**

A variable force F acts through a displacement d. The magnitude of the force is proportional to the displacement, so F=kd, where k is constant. a) Sketch a graph of this force against position up to position x. b) According to the equation, what is the value of the force at x...

*October 6, 2010*

**Physics - gravitational potential energy**

When developing the equation for gravitational potential energy, why is it necessary to assume that the mass is rising at a constant speed?

*October 6, 2010*

**Physics **

If the force of friction is constant, prove that the stopping distance of a car on a level road varies directly with the square of the initial speed.

*October 6, 2010*

**Physics - Inelastic **

Imagine that you have a very powerful water pistol. Describe in detail the experiment that you could perform, including the measurements that you would make, to determine the velocity of the water as it leaves the pistol.

*October 4, 2010*

**Physics **

A car with mass of 1875kg is traveling along a country road when the driver sees a deer dart out onto the road. The driver slams on the brakes manages to stop before hitting the deer. The driver of a second car with 2135kg is driving too close and does not see the deer. When ...

*October 4, 2010*

**Physics - Inelastic Collision ( check + help)**

How is it possible that mass which is 0.155kg is not taken into consideration? You solve it as a 2D collision and thereafter you obtain the two equations, two variables and you solve you will get V' Thereafter you find if it is elastic or not by equating the kinetic energy

*September 26, 2010*

**Physics - Inelastic Collision ( check + help)**

A billiard ball of mass 0.55kg moves with a velocity of 12.5m/s towards a stationary billiard ball of the identical mass and strikes it with a glancing blow. The first billiard ball moves of at an angle of 29.7deg clockwise from its original direction, with a velocity of 9.56m...

*September 26, 2010*

**Math - Instantaneous and average rates of change**

a) Describe a graph for which the average rate of change is equal to instantaneous rate of change for its entire domain. Describe a real life situation that this graph could represent. b) Describe a graph which the average rate of change between two points is equal to the ...

*September 26, 2010*

**Physics - Inelastic Collisions**

The speed of a pitched baseball is 46.0m/s. You want to know how fast is your school's star baseball pitcher could throw. You make a pendulum with a rope and a small box lined with a thick layer of soft clay, so that the baseball would stick to the inside of the box. The ...

*September 22, 2010*

**Physics - Inelastic Collisions**

The speed of a pitched baseball is 46.0m/s. You want to know how fast is your school's star baseball pitcher could throw. You make a pendulum with a rope and a small box lined with a thick layer of soft clay, so that the baseball would stick to the inside of the box. The ...

*September 20, 2010*

**Math - Intersection of planes**

You are given the following two planes: x+4y-3z-12=0 x+6y-2z-22=0 a) Use the two original equations to determine two other equations that have the same solution as the original two. ANS: the original two are not parallel in anyway so can I just take multiples of the original ...

*September 20, 2010*

**Physics - Power Law Data Analysis**

Can I make my x value as 3sqrtx, I will get the same straight line? Is that possible, if I use log and the 3sqrtx i get different values of b, which one is more accurate?

*September 20, 2010*

**Physics - Power Law Data Analysis**

In an experiment, two variable quantities, x and y were measured. The relation between x and y is thought to be: y= 4(pi)b(x)^3 x(cm) +/- 0.02cm 0.67 0.80 0.90 0.95 y(g) +/- 0.25g 2.25 4.00 5.52 6.60 a) Draw a complete table that allows you to plot the graph which could be ...

*September 20, 2010*

**Math - Rates os change**

a) Describe a graph for which the average rate of change is equal to instantaneous rate of change for its entire domain. Describe a real life situation that this graph could represent. b) Describe a graph which the average rate of change between two points is equal to the ...

*September 16, 2010*

**Math - Rates of change using equations**

s(t)= -4.9t^2+15t+1 - write an expression to represent the average rate of change over the interval '1' less than or equal to 't' less than or equal to '1+h'

*September 16, 2010*

**Math - Intersection of planes**

You are given the following two planes: x+4y-3z-12=0 x+6y-2z-22=0 a) Use the two original equations to determine two other equations that have the same solution as the original two. ANS: the orginal two are not parallel in anyway so can I just take multiples of the original ...

*September 15, 2010*

**Physics: Data Analysis - Power Law**

please check and correct a) in the x-axis i will have the sqrt'x' and the y-axis the 'y' variable b) i make a table with the value of sqrt of 'x' and the given y values c) just plot the points but how do i find the constant, i tried it algebraically i ...

*September 13, 2010*

**Physics: Data Analysis - Power Law**

In an experiment, two variables quantities 'x' and 'y' were measure. The relation between x and y is thought to be y=ax^(1/2) x(m)+/- 0.01m 0.10 0.20 0.40 0.80 1.00 y(s) +/- 0.05s 0.64 0.90 1.27 1.80 1.90 a) What will you graph in the y- and x- axis in order to...

*September 13, 2010*

**Physics - Data Analaysis - Power Laws**

In an experiment, two variables quantities 'x' and 'y' were measure. The relation between x and y is thought to be y=ax^(1/2) x(m)+/- 0.01m y(s) +/- 0.05s 0.10 0.64 0.20 0.90 0.40 1.27 0.80 1.80 1.00 1.90 a) What will you graph in the y- and x- axis in order to...

*September 11, 2010*

**Math - system of equations**

write two other equations that have the same solution as this system od equations. 3x-4y=-14 -x+3y=18 I found the solution to the system it is (6,8) there after how do i go about it?

*September 7, 2010*

**Physics - application of Momentum**

Could the question be true when the mass is not constant, say maybe in the case of cars. When two cars collide, their masses change but their resultant momentum would be the same before and after the crash so you could you delta p, and the time. Would that be a possible answer?

*September 7, 2010*

**Physics - application of Momentum**

Could this be a possible answer for the above question. When catching a ball with bare hands hurts, because it has some force. Since the the ball will always approach one at the same speed, therefore its change in momentum deltaP= Vfinal - Vinitital where Vfinal is zero. Thus ...

*September 7, 2010*

**Physics - application of Momentum**

Try to imagine a situation in which the form f=ma would no apply, but the form f=delta p / delta t could be used. Describe that situation. How could you test your prediction.

*September 7, 2010*

**Math - Equations of plane(check)**

for the e part of the question you mean: [x,y,z]=[2,3,1]+t[10,2,0]+s[5,1,0] right??

*September 6, 2010*

**Math - Equations of plane(check)**

Consider the plane that contains points A(2,3,1), B(-11,1,2), C(-7,-3,-6). a) Find two vectors that are parallel to the plane. Ans: AC, BC or AB will be parallel to the plane. b) Find two vectors that are perpendicular to the plane. Ans: if i find the normal vector then i can...

*September 6, 2010*

**Math - intersection of planes**

You are given the following two planes: x+4y-3z-12=0 x+6y-2z-22=0 a) Determine if the planes are parallel b) Fine the line of intersection of the two

*September 6, 2010*

**Math - equation of plane and vectors**

If i want to find the x-, y- and z- intercepts do i write a new vector equation because we previously found the intercepts but the x-intercept =16 y-intercept = -4 and the z-intercept = 8 i tried writing a vector equation using the one vector as my point and the scalar ...

*September 5, 2010*

**Math - equation of plane and vectors**

A plane is defined by the equations x-4y+2z=16. Find two vectors parallel to the plane.

*September 5, 2010*

**Math - equations of lines**

Writing the parametric equations of the given line one x=-21-12t and since we want the x intercept the y=z=0 therefore 8+4t=0 and 14+7t=0 in both case the t value is '-2' repeating the similar procedure to find the y-intercept the value of s=-3 there after how do i ...

*September 5, 2010*

**Math - equations of lines**

A line has the same x-intercept as [x,y,z]=[-21,8,14]+t[-12,4,7] and the same y-intercept as [x,y,z]=[6,-8,12]+s[2,-5,4]. Write the parametric equation of the line.

*September 5, 2010*

**Math - vector equation of a parallelogram**

Isn't there another way to find the vector equation because they are the correct coordinates sample answers are: [x,y]=[-1,4]+t[1,-1] [x,y]=[-1,4]+t[2,1]

*September 5, 2010*

**Math - vector equation of a parallelogram**

The vertices of a parallelogram are the origin and the points A(-1,4), B(3,6), and C(7,2). Write the vector equations of the lines that make up the sides of the parallelogram

*September 5, 2010*

**Math - intersection of planes**

You are given the following two planes: x+4y-3z-12=0 x+6y-2z-22=0 a) Determine if the planes are parallel b) Fine the line of intersection of the two planes. c) Use the two original equations to determine two other equations that have the same solution as the original two. d) ...

*September 4, 2010*

**Math - Equations of plane(check)**

Consider the plane that contains points A(2,3,1), B(-11,1,2), C(-7,-3,-6). a) Find two vectors that are parallel to the plane. Ans: AC, BC or AB will be parallel to the plane. b) Find two vectors that are perpendicular to the plane. Ans: if i find the normal vector then i can ...

*September 4, 2010*

**Math - equation of plane and vectors**

A plane is defined by the equations x-4y+2z=16. Find two vectors parallel to the plane.

*September 4, 2010*

**Math - equations of lines**

A line has the same x-intercept as [x,y,z]=[-21,8,14]+t[-12,4,7] and the same y-intercept as [x,y,z]=[6,-8,12]+s[2,-5,4]. Write the parametric equation of the line.

*September 4, 2010*

**Math - vector equation of a parallelogram**

The vertices of a parallelogram are the origin and the points A(-1,4), B(3,6), and C(7,2). Write the vector equations of the lines that make up the sides of the parallelogram

*September 4, 2010*

**Physics - elastic collision**

Since the directions are north and west you directly use the Pythagoras theorem to find the resultant speed?? and the tan of the two two get the angle??

*September 4, 2010*

**Physics - elastic collision**

Car A, with mass of 1735kg, was traveling north at 45.5km/h and car B, with a mass of 2540kg, was traveling west at 37.7km/h when they collided at an intersection. if the cars stuck together after the collision, what was their combined momentum? Was the collision elastic or ...

*September 4, 2010*

**Physics - Elastic Collision**

how is this equation derived V'2= V1(2M1)/(M1+M2) (elastic collision - where one object is moving and the other is stationary)

*September 4, 2010*

**Physics - Momentum of cars at intersection**

Car A(1750kg) traveling due south and car B (1450kg)due east. They reach the same intersection at the same time and collide. The cars lock together and move off at 35.8km/h[E31.6degS]. What was the velocity of each car before the collided? I tried this question using the law ...

*September 1, 2010*

**Physics - Momentum of cars at intersection**

Two cars of identical mass are approaching the same intersection, one from the south and the one from the west. They reach the intersection at the same time and collide. The cars lock together and move away at an angle of 22deg counterclockwise from the road; heading east. ...

*September 1, 2010*

**Physics - Momentum**

Under what circumstances is the change in momentum of a system equal to zero?

*September 1, 2010*

**Math- intersection of planes**

Show that the line [x,y,z]=[10,5,16]+t[3,1,5] is contained in the plane x+2y-z-4=0 I tries writing the vector equation in parametric form and then substituting it into the respective x,y,z in the plane, after simplifying I get 0t=0 does this mean that the line is in the plane ...

*September 1, 2010*

**Math - Intersection of planes**

Find the vector equation of the line of intersection for the pair of planes. Plane one: x+5y-3z-8=0 Plane two: y+2z-4=0 I did half of the work but now i am stuck. the normal of the planes are not parallel and therefore a solution exists, you simultaneously solve the equations...

*September 1, 2010*

**Physics - Rube Goldberg Project**

I need to make a Rube Goldberg Machine and it must demonstrate projectile motion, conservation of energy and conservation momentum, any idea on what to make and how to make it? Help please

*August 31, 2010*

**Math - distances between two planes**

Find the distances between planes. plane 1: 2x-y-z-1=0 plane 2: 2x-y-z-4=0

*August 28, 2010*

**Math - distance b etween a line and plane**

Find the distance between the parallel line and the plane. line: vector r = [2,0,1]+t[1,4,1] plane: 2x-y+2z=4

*August 28, 2010*

**Math- Intesection of a plane and line**

Does the line [x,y,z]=[5,-9,3]+k[1,-12,2] intersect the plane [x,y,z]=[4,-15,8]+s[1,-3,1]+t[2,3,1]? If so, how many solutions are there? ( I tried finding the normal vector, there after finding the "d" value to write in scalar equation, and once it is in scalar ...

*August 28, 2010*

**Math - number of solution**

Determine the number of solutions for the system without solving. 3x+12y=-27 4x+2y=34

*August 28, 2010*

**Math - interection of two lines**

Determine if L1 [x,y,z]=[4,-3,2]+t[1,8,-3] and L2 [x,y,z]=[2,-19,8]+s[4,-5,-9] intersect

*August 28, 2010*

**Math - Solving Linear systems**

Solve the linear system in two space [x,y] = [-12,-7] + s[8,-5] [x,y] = [2,-1] + t[3,-2]

*August 28, 2010*

**Math - Equations of planes**

Write a vector equation and scalar equation of the plane containing lines [x,y,z]= [-2,3,12]+s[-2,1,5] [x,y,z]= [1,-4,4]+t[-6,3,15]

*August 27, 2010*

**Physics - Applications of Momentum**

Use the concept of impulse to explain the difference in the results of a jump using a proper bungee cord and a jump using ordinary rope. (Ans: Is it that impulse is equal to mVf - mVi and the final velocity will be zero for the ordinary rope, however when using the bungee cord...

*August 25, 2010*

**Physics - Momentum**

Try to imagine a situation in which the form f=ma would no apply, but the form f=delta p / delta t could be used. Describe that situation. How could you test your prediction.

*August 25, 2010*

**Physics - Momentum**

Define momentum qualitatively and quanititatively. (qualitatively - a measure of an object's mass to resist changes in its velocity or acceleration. Is this correct? How do I define momentum quantitatively)

*August 25, 2010*

**Maths - Properties of Planes**

Wrtie a scalar equation given it's parametric equation. x = 3-2s+2t y = 1+3s+t z = 5-s-2t

*August 24, 2010*

**Maths - Properties of Planes**

write a scalar equation, given it's vector equation. [x,y,z]= [3,7,-5] + s[1,2,-1] + t[5,-2,3] ( I remember my teacher saying that you have to cross s and t, and that will be my normal and thereafter I substitue the point to find the 'D' value of the scalar ...

*August 24, 2010*

**Physics - Satellite Motion**

Calculate the acceleration of two different satellites that orbit Earth. one is located at 2.0Earth radii and the other located 4.0Earth radii.

*August 24, 2010*

**Physics - Forces**

A 42kg girl jumps on a trampoline, after stretching to its bottom limit; the trampoline exerts an average upward force on the girl over a diplacement of 0.50m. During the time that the trampoline is pushing her up, se experiences an average acceleration of 65.0m/s^2. Her ...

*August 24, 2010*

**physics - uniform circular motion**

Explain why the kinematics equations which describe the motion of the object that has constant acceleration cannot be applied to uniform circular motion.

*August 23, 2010*

**physics - newtons 3rd law**

According to Newton's third law, for every action force there is a reacgtion force, then how can a team win a tug of war contest

*August 23, 2010*

**Physics - frames of reference**

A car turns off the highway onto a curved exit ramp. a) What type of motion does the passangers' fram of reference experience relative to the ground? b) Explain why the passangers feel a force to the right as the car turns. c) How would an observer on an overpass describe ...

*August 23, 2010*

**Physcis - Planets**

How could you discover a planet without seeing it with a telescope?

*August 23, 2010*

**Physics - Geostationary Satellite**

Why must a geostationary satellite orbit over the equator?

*August 23, 2010*

**Physics - Planetary Motion**

The planet Neptune has an orbital radiu around the sun of about 4.50 * 10^12m. What are its period and its orbital speed?

*August 23, 2010*

**Physics - Satellite Motion**

The polar- orbiting environmental satellites (POES) and some military satellites orbit at a much lower level in order to obtain more detailed information. POES complete an Earth orbit 14.1 times per day. What are the orbital speed and the ltitude of the POES?

*August 23, 2010*

**Physics - weighing a planet**

Explain how you can weigh a planet? ( Is it by the combination of the netwons law of univeral gravitation and keplers third law; t^2/r^3 = 4(pi)^2/G(Msun) )

*August 22, 2010*

**Physics - Newton's Law of universal gravitation**

Describe how Newton used each of the following phenomena to support the law of universal gravitation a) the orbit of the moon b) kepler's third law

*August 22, 2010*

**Physics - Cavendish experiment**

Describe the objective, apparatus and results of the Cavendish experiment

*August 22, 2010*

**Physics - Gravitational force**

Find the gravitational force between earth and the sun. I am using the formula Fg = (G*m1*m2)/(r^2) where G = 6.67*10^-11 m1 = 6.0*10^24kg m2 = 2.0*10^30kg r = should i use the sun's radius or the earths (Rearth = 6.38*10^6; Rsun = 6.96*10^8) either way i use i am not ...

*August 21, 2010*

**Physics - banked curves**

Sharp turns are banked more steeply because when turning the vertical component does not matter, however it is the horizontal component should be balanced otherwise the car skids on in the horizontal direction??

*August 21, 2010*

**Physics - banked curves**

On a highway, why are sharp turns banked more steeply than gentle turns?

*August 21, 2010*

**Physics - Centrifugal force**

A centrifugal force, if it existed, would be directed raidally outward from the centre of the circle during a circular motion. Explain why it feels as though you are being thrown outward when you are riding on an amusment park ride that causes you to spin in a circle.

*August 21, 2010*

**Physics - Uniform circular motion**

If you were swingin a ball on a string around in a circle in a vertical plane, at what point in the path would the string be the most likelt to break? Explain why In what direction would the ball fly when the string broke?

*August 21, 2010*

**Physics - Uniform circular motion**

What type of acceleration is associated with uniform circular motion?

*August 21, 2010*

**Physics - maximum height of the projectile motion**

Suppose you knew the maximum height reached by a proejctile. Could you find its launch angle from this information alone? If not, what additional information would be required? (No it is not enough, the initial velocity? i also think yes because the highest the angle can be is...

*August 21, 2010*

**Physics - Range of projectile motion**

What properties of projectile motion must you apply when deriving an equation for the range of a projectile? (is it the trignometric identity??)

*August 21, 2010*

**Physics - rojectile Motion (check pls)**

It is a communication worth question so i have to be wordy! btw - i got the answer of the projectile motion of the baseball! I was using sine of the angle multiplied by time instead of cosine in the horizontal component Thank you!

*August 21, 2010*

**Physics - rojectile Motion (check pls)**

Imagine that you are solving a problem in projectile motion in which you are asked to find the time at which a projectile reaches a certain vertical position. when you solve the problem you find out two different positive values for time that both satisfy the condition of the ...

*August 21, 2010*

**English - Thesis Statement on Life of Pi**

a) how is life of pi a story within a story within story? ( i know the first part a story within a story, but the other within the story, i am confused) b) i am going to write an essay about story telling on Life of Pi by Yann Martel and so far have ideas such as the type of ...

*August 21, 2010*

**English - Book Choice**

Can anyone suggest names of books which include friendship between two women, or a book written by an American African.

*August 21, 2010*

**Physics - Projectile Motion**

During baseball practice, you go up into the bleachers to retrieve a ball. You throw the ball back into the playing field at an angle of 42deg above the horizontal, giving it an initial velocity of 15m/s. If the ball is 5.3m above the level of the playing field when you throw ...

*August 19, 2010*

**Physics - Projectile Motion**

While Hiking in the wilderness, you come to the top of a cliff that is 60.0m high. you throw a stone from the cliff, giving it an initial velocity of 21m/s at 35deg above the horizontal. How far from the base of the cliff does the stone land? (85m) I tried this question but i ...

*August 19, 2010*

**English - Life of Pi and religion**

What is the role of christainity in Life of Pi?

*August 16, 2010*

**English - Life of Pi suggestions**

I need to write an essay for life of pi which is five to six pages long, could anyone please give me suggestions what to write about, I find the practice of religion interesting as well as the sorry telling vs the reality but i do not know how to formulate a thesis and to use ...

*August 16, 2010*

**English - book suggestions**

Book suggestions to read with Sula by Toni Morrison, i have to read a second book realted to the above book either in themes or in criticism. Can anyone give me a list of a couple of books i could choose from?

*August 16, 2010*

**Physics - Inclined Motions**

You are pushing a 53kg crate at a constant velocity up a ramp onto a truck. The ramp makes an angle of 22deg with the horizontal. If your applied force is 373N, what is then coefficient of friction between the crate and the ramp?

*August 11, 2010*

**Physics - Modern Society**

By the mid-1800s, steam driven elevators with counterweights had been developed. However, they were not in common use until 1852, when Elisha Otis invented an elevator from falling if the cable broke. How do you think that the invention of a safe elevator changed the modern ...

*August 11, 2010*

**Physics**

Two objects are moving in different direction. Under what circumstances can you treat this as one-dimensional problem?

*August 11, 2010*

**Physics - gravitational acceleration**

How does and Atwood machine make it easier to determine g - the acceleration due to gravity, rather than by just measuring the acceleration of a free-falling object?

*August 11, 2010*

**Physics - Vertical Motion**

A 64kg person is standing on a scale in an elevator. the elevator is rising at a constant velocity but then begins to slow, with an acceleration of 0.59m/s^2. What is the sign of the acceleration? What is the reading on the scale while the elevator is accelerating.

*August 11, 2010*

**Math - Vectors**

Resolve vector u =[3,4,7] into rectangular components, on which is collinear with vector v =[1,2,3].

*August 10, 2010*

**Math - Vectors**

Prove that vector i,j and k are mutually orthogonal using the dot product. What is actually meant by mutually orthogonal?

*August 10, 2010*

**Calculus - Dot Product**

A crate is dragged 3m along a smooth level floor by a 30n force applied at 25deg to the floor. Then it is pulled 4m up a ramp inclined at 20deg to the horizontal, using the same force. Then, the crate is dragged a further 5m along a level platform using the same force. ...

*August 9, 2010*

**vectors in three space**

a) Describe the form of the coordinates of all points that are equidistant from the x- and y-axes. b) Describe the form of the coordinated of ll points that are equidistant from the x-, y- and z-axes.

*August 9, 2010*