# Shaila

Popular questions and responses by Shaila-
## 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]

*asked on August 27, 2010* -
## Dot Product 1

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

*asked on August 9, 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

*asked on August 11, 2010* -
## Math - Vectors

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

*asked on August 10, 2010* -
## Resolution of vectors

A 1000kg load is suspended from the end of a horizontal boom. The boom is supported by a cable that makes an angle of 35deg with the boom. a) what is the tension in the cable? b) what is the horizontal force on the boom?

*asked on July 29, 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.

*asked on September 5, 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?

*asked on August 11, 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

*asked on September 6, 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.

*asked on September 5, 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.

*asked on October 6, 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,

*asked on 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

*asked on September 26, 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.

*asked on 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)

*asked on 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

*asked on September 1, 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

*asked on August 24, 2010* -
## cartesian vectors 2

let vector U = (vector u1, vector u2) vector V = (vector v1, vector v2) and vector W = (vector w1, vector w2) Prove each property using Cartesian vectors: a) (vector U+V)+W = vector U+(v+W) b) k(vector U+V) = k vector U + k vector V c) (k+m)vector U = k

*asked on July 31, 2010* -
## Advanced Function

find the x-intercepts of: x^4-2x^3-8x^2+12x-16

*asked on May 29, 2010* -
## Physics - Momentum

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

*asked on 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

*asked on 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

*asked on 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

*asked on August 31, 2010* -
## Math - number of solution

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

*asked on August 28, 2010* -
## Physics - banked curves

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

*asked on August 21, 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

*asked on August 19, 2010* -
## Physics - frictional force

Pushing a grocery cart with a force of 95N applied at an angle of 35deg own from the horizontal, makes the cart travel at a constant speed of 1.2m/s. What is the frictional force acting on the cart?

*asked on August 5, 2010* -
## addition and subtraction of vectors

In a soccer match, the goal keeper stands on the midpoint of her goal line. she kicks the ball 25m at an angle of 35deg to the goal line. her teammate takes the pass and kicks it 40m farther, parallel to the sideline. The resultant vector is 62.2m if the

*asked on July 29, 2010* -
## 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 .

*asked on November 22, 2011* -
## 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

*asked on 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?

*asked on 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.

*asked on 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

*asked on October 4, 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

*asked on 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

*asked on 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

*asked on 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

*asked on 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

*asked on 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'

*asked on 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

*asked on September 15, 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

*asked on 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

*asked on 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?

*asked on 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.

*asked on September 7, 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

*asked on September 6, 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

*asked on 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

*asked on 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

*asked on 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.

*asked on 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

*asked on 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

*asked on September 4, 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

*asked on September 1, 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

*asked on 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

*asked on 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

*asked on 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

*asked on 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]

*asked on August 28, 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

*asked on 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.

*asked on 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)

*asked on 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

*asked on 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

*asked on 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.

*asked on 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.

*asked on 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

*asked on 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

*asked on August 23, 2010* -
## Physcis - Planets

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

*asked on August 23, 2010* -
## Physics - Geostationary Satellite

Why must a geostationary satellite orbit over the equator?

*asked on 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?

*asked on 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

*asked on 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) )

*asked on 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

*asked on August 22, 2010* -
## Physics - Cavendish experiment

Describe the objective, apparatus and results of the Cavendish experiment

*asked on 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

*asked on 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

*asked on 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?

*asked on August 21, 2010* -
## Physics - Uniform circular motion

What type of acceleration is associated with uniform circular motion?

*asked on 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

*asked on 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??)

*asked on 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

*asked on 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

*asked on 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.

*asked on 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

*asked on August 19, 2010* -
## English - Life of Pi and religion

What is the role of christainity in Life of Pi?

*asked on 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

*asked on 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?

*asked on August 16, 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

*asked on August 11, 2010* -
## Physics

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

*asked on 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?

*asked on August 11, 2010* -
## Math - Vectors

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

*asked on 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

*asked on 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.

*asked on August 9, 2010* -
## Dot Product

Determine the interior angles of triangle ABC for a(5,1) b(4,-7) and c(-1,-8)

*asked on August 9, 2010* -
## Calculus - Dot Product

consider a rhombus ABCD a) find the resultant of vector AB + vector AD and vector AB - vector AD? (cosine rule) b) What will be the value of the dot product of vector AB + vector AD and vector AB - vector AD always be? (always zero) c) Is this value of the

*asked on August 9, 2010* -
## Physics - Relative velocity

A barge is heading directly across a river at35km/h while you are walking on the barge at 4km/h in the same direction as the barge is heading. The current is flowing downstream at 1.4km/h. a) What is your velocity relative to the shore? (7.6km/h) b) What

*asked on August 9, 2010* -
## Physics

Three identical blocks, fastened together by a string, are pulled across a frictionless surface by a constant force. Compare the tension on string A to magnitude of applied force F.

*asked on August 5, 2010* -
## Physics - Force

A 0.30kg lab cart is observed to accelerate twice as fast as a 0.60kg cart. Does that mean that the net force on the more massive cart is twice as large as the force on the smaller cart? Explain.

*asked on August 5, 2010* -
## Physics - reaction force

When you pull on a rope, the rope pulls back on you. Describe how the rope creates this reaction force.

*asked on August 5, 2010* -
## Physics - ice skating

An ice skater pulls three small children, one behind the other, with masses 25kg, 31kg, and 35kg. Assume that the ice is smooth enough to be considered frictionless. If the skater is holding onto the 25kg child, find the tension in the arms of the next

*asked on August 5, 2010* -
## Physics - Inertial frame of reference

Identify the defining characteristic of inertial and non-inertial frames of reference. Give an example of each type of frame of reference.

*asked on August 3, 2010* -
## Physics - stage trick

A stage trick involves covering a table with a smooth cloth. When the cloth is suddenyl pulled horizontally, the dishes "magically" stay in position and drop on to the table. a)identify all the forces acting on the dishes during the trick b)explain ho

*asked on August 3, 2010*

## Pages

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