Wednesday

July 27, 2016
Total # Posts: 1,253

**physics**

A 60 kg student does 60 push ups in 40s . With each push up , the student must lift 70% of the body mass a height of 40cm off the floor. Assuming two significant digits, calculate the following The work the student does against a force of gravity for each push up , assuming ...
*April 25, 2012*

**Chemistry**

If the acetylene were burned to form water and carbon dioxide, how many kilojoules of energy would be produced from the complete reaction of 20 of calcium carbide? CaC2(s)+2H2O(l) --> C2H2(g)+Ca(OH)2(s)
*April 23, 2012*

**Chemistry**

If the acetylene were burned to form water and carbon dioxide, how many kilojoules of energy would be produced from the complete reaction of 20 of calcium carbide? CaC2(s)+2H2O(l) --> C2H2(g)+Ca(OH)2(s)
*April 23, 2012*

**Physics**

Viscous blood is flowing through an artery partially clogged by cholesterol. A surgeon wants to remove enough of the cholesterol to double the flow rate of blood through this artery. If the original diameter of the artery is D , what should be the new diameter (in terms of D...
*April 23, 2012*

**math**

a rectangular field measures 20 meters by y meters is surrounded by grass patch of width 2 meters . What is the area of the grass patch ? Leave your answer in the simplest form in terms of y .
*April 21, 2012*

**math**

from one piece of wood , Sam cut two 9 1/2 in. strips for 2 sides of a frame. He cut two 11 3/4 in . strips each for the other 2 sides Sam had 5 1/2 in.of wood left. How long was the piece of wood when he started ?
*April 18, 2012*

**math**

1. Gina wants to begin by figuring out how long the corn bed will be. She knows that in her previous two gardens, she was able to plant 2 rows in a 5 foot long space and 5 rows in an 11 foot long space. Find a linear equation for the length of the bed (y) in which she can fit ...
*April 16, 2012*

**Chemistry**

This answer is still not correct for me!!
*April 15, 2012*

**statistics**

20. Explain how the power of a hypothesis test is influenced by each of the following. Assume that all other factors are held constant. a. Increasing the alpha level from .01 to .05. b. Changing from a one-tailed test to a two-tailed test.
*April 14, 2012*

**physics**

Write the energy transformation equation for each situation Fireworks explodes An arrow is shot off a bow and flies through the air A paved driveway feels hot on a clear ,sunny day A camper raises an axe to chop a chunk of wood A lawn mower with a gasoline engine cuts a lawn
*April 12, 2012*

**Physics**

how does the slope of a Ff-Fg graph relate to the coefficients of friction , prove it mathematically.
*April 12, 2012*

**physics**

A 12 kg toboggan is pulled along at a constant velocity on a horizontal surface by a horizontal force of 11 N How much horizontal force is needed to pull the toboggan at a constant velocity if two 57 kg girls are sitting in it ?
*April 10, 2012*

**science**

a 40kg student goes to jupiter where the rate of acceleration is 24.5m/s squared what is the students weight on jupiter?
*April 10, 2012*

**chemistry**

Which of the following measures thermal energy in an object? (Points : 4) temperature mass heat volume
*April 9, 2012*

**physics**

A wagon is used to help deliver papers. There is a force applied at an angle of 25 degrees to the horizontal that causes the wagon to move a distance of 15m[N] in 10.0s from rest. There is a force of friction of 3.1 N acting on the 27kg wagon. What is the acceleration of the ...
*April 9, 2012*

**Calculus**

Verify if correct. Determine which line is parallel to the line with Cartesian equation 2x +3y + 5=0 a) r=(-1,-1) +s(2,3), seR b) x=3t-1, y=-2t-1, teR c) x=2t-1, 3t-1, teR d) none of the above. I chose D, none of the above because none of them are multiples of the given ...
*April 7, 2012*

**Calculus**

Explain fully please and thank you! =) Determine the point of intersection of the lines L1: r= (1,3,7) + s(1,2,-2),seR and L2: v=(0,2,-3) +t(1,1,4), teR. a) P(1,3,1) b P(1,3,7) c) The lines coincide d) no point of intersection
*April 7, 2012*

**physics**

Determine the magnitude of the force of gravity acting on a 340 kg satellite , 850 km above Earth's surface.
*April 6, 2012*

**physics**

A tug of war has started over a popular toy. One child pulls with a force of 2.0*10^1 N[W], a second child pulls with a force of 15N[N] and a third child pulls with a force of 4.0*10^1 N [30 S of E] calculate the net force on the toy
*April 5, 2012*

**physics**

If the coefficient of kinetic friction is 0.25 , how much horizontal force is needed to pull each of the following masses along a rough desk at a constant speed? A) 25 kg
*April 5, 2012*

**physics**

A 650 N student is Rollerblading at a velocity of 7.8 m/s [W] when the student trips and slides horizontally along the trail, coming to a stop 0.95s. Determine the students average acceleration
*April 5, 2012*

**physics**

Determine the magnitude of the force of gravity acting on a 340 kg satellite, 850 km above Earth's surface
*April 5, 2012*

**physics**

How do i find the acceleration though
*April 4, 2012*

**physics**

Given the following forces acting on an object find the net force: 2.0N[N], 10N[S], 2.0N[W], 8.0N[E] The mass is 5.1 kg with the net force find the objects acceleration
*April 4, 2012*

**physics**

Two children on the beach are pulling on an inner tube. One exerts a force of 45 N[N]. The other exerts a force of 60N[SW]. What is the net force acting on the tube
*April 3, 2012*

**physics**

Two children on the beach are pulling on an inner tube. One exerts a force of 45 N[N]. The other exerts a force of 60N[SW]. What is the net force acting on the tube
*April 3, 2012*

**physics**

Two children on the beach are pulling on an inner tube. One exerts a force of 45 N[N]. The other exerts a force of 60N[SW]. What is the net force acting on the tube
*April 3, 2012*

**physics**

Two children on the beach are pulling on an inner tube. One exerts a force of 45 N[N]. The other exerts a force of 60N[SW]. What is the net force acting on the tube
*April 3, 2012*

**physics**

Two children on the beach are pulling on an inner tube. One exerts a force of 45 N[N]. The other exerts a force of 60N[SW]. What is the net force acting on the tube
*April 3, 2012*

**physics**

The force of gravity at Earth's surface on an astronaut is 634N. What is the force of gravity on the same person at each of the following distances, in multiples of Earth's radius, from the centre of Earth? A)2 B)5 C)10 D)17.2
*April 2, 2012*

**physics**

The mass of Earth can be calculated using the fact that the weight of an object (in newtons) is equal to the force of gravity between the object and Earth. Given that the radius of Earth is 6.4*10^6m , determine its mass
*April 2, 2012*

**physics**

Any my text book for the 12.0kg steel ball it says the answer is 1.2*10^2N, not 117.6N how did they get that answer?
*April 1, 2012*

**physics**

Calculate Earth's force of gravity on each of two steel balls of masses 6.0kg and 12.0kg I the forces of gravity on the 12-kg ball is greater than that on the other ball, why do the two balls accelerate at the same rate when dropped?
*April 1, 2012*

**trig**

389 miles
*March 28, 2012*

**Trigonometry **

A ladder that is 15 feet long is placed so that it reaches from level ground to the top of a vertical wall that is 13 feet high A. Use the law of sines to find the angle that the ladder makes with the ground to the nearest hundredth B. Is more than one position of the ladder ...
*March 27, 2012*

**physics**

When the crampton coal-fired train engine was built in 1852 , its mass was 48.3t ( 1.0 t= 1.0*10^3) and its force capability was rated at 22.4 kN. Assuming it was pulling train cars whose total mass doubled its own was and the total friction on the engine and cars was 10.1 kN...
*March 25, 2012*

**physics**

When the crampton coal-fired train engine was built in 1852 , its mass was 48.3t ( 1.0 t= 1.0*10^3) and its force capability was rated at 22.4 kN. Assuming it was pulling train cars whose total mass doubled its own was and the total friction on the engine and cars was 10.1 kN...
*March 25, 2012*

**physics**

Lol :) thanks , i should have thought of that
*March 25, 2012*

**physics**

According to newtons 1st law , construction workers are warned not to leave their hard hats on the rear window ledge of their cars, explain why?
*March 25, 2012*

**physics**

Sorry i meant 4000 kg is the mass
*March 25, 2012*

**physics**

A jet plane pilot decides to accelerate horizontally. If the thrust of the engine is increased to 50 000 N at a time when the air resistance ( or drag) acting on the 4000kg plane amounts to 30 000 N , what will the planes acceleration be I believe you at the 50 000 and the 30 ...
*March 25, 2012*

**physics**

Thank you so much I understand now !
*March 25, 2012*

**physics**

How much applied force is needed to accelerate a 2.0 kg block of wood at 4.0m/s^2 along a rough table, against a 10 N force of friction?
*March 25, 2012*

**physics**

Thank you for helping me ! It takes me a little bit longer to grasp concepts, i think now the correct answer is it is unbalanced because it accelerates?
*March 25, 2012*

**physics**

Is the net forces balanced because it accelerates steadily in a straight line?.
*March 25, 2012*

**physics**

I have no clue we never covered it in class!
*March 25, 2012*

**physics**

A 1200 kg boat accelerates steadily at 0.05 m/s^2 in a straight line . Are the forces on this boat balanced or unbalanced?
*March 25, 2012*

**physics**

The force of friction is zero?
*March 25, 2012*

**physics**

A woman pushes a refrigerator across the floor at a steady speed of 20cm/s . If she has to push with a horizontal force of 400 N to keep it moving , is the force of friction less than 400 N , 400 N, more than 400 N, why
*March 25, 2012*

**physics**

Thank you so much, i understand a lot more now !
*March 25, 2012*

**physics**

A jet plane is traveling at a constant speed in a straight line in level speed. What does this tell you about the forces acting on it, what forces are acting on it .
*March 25, 2012*

**physics**

thank you bobpursley
*March 23, 2012*

**physics**

A triathlete swims 1200 m due to east followed by 1500 m due northeast (45o). What is the overall displacement? (magnitude and angle). Calculate the displacement with long-hand calculations.
*March 23, 2012*

**physics**

Thanks bobpursely I need this for my Quantitative Biomechanics class
*March 23, 2012*

**physics**

A diver is jumping straight up with 2 m/s from a 15 meter platform. Calculate the maximum height of the diver, the diver’s velocity when reaches the water, and total time to reach the water.
*March 23, 2012*

**Calculus**

A rectangular prism is defined by vectors (2,0,0) (0,9,6) and (0,0,3). Find the volume.
*March 22, 2012*

**Geometry**

The height of the segment from the apex of the cone to the base is 10 feet. The length of the diameter of the circular base is 4 feet. Calculate the volume
*March 22, 2012*

**Geometry**

The height of the segment from the apex of the pyramid to the base is 10 feet. The length of the diagonal of the square base is 4 feet. Calculate the volume
*March 22, 2012*

**geometry**

a ladder is 53 inches. how tall is it in feet and inches
*March 20, 2012*

**Calculus and vectors**

I don't know, I think that it is A-B=C
*March 18, 2012*

**Calculus and vectors**

Explain how the vector C⃗(Going from the head of B⃗ to the head of A⃗) can be written in terms of vectors A⃗ and B⃗ Given the shape in this url: imgur dot com/5nT3V
*March 18, 2012*

**Calculus and vectors**

Please, help I don't understand vectors T.T 1. In the prism, assume all dimensions have different lengths, state the following: a) state 3 equal vectors to DC⃗ b) state 4 opposite vectors to BC⃗ ------------------------------------- Here is the prism below, ...
*March 18, 2012*

**art history**

How would you compare and contrast the northern and southern style temple?
*March 15, 2012*

**Physics**

A athlete in good physical condition can land on the ground at a speed of 12m/s without injury , calculate the max height from which the athlete can jump without injury, assuming the takeoff speed is zero
*March 12, 2012*

**Physics**

A student throws a baseball vertically upward, and 2.8s later catches it at the same level. Neglecting air resistance , calculate the following (a) the velocity at which the ball left the students hand (b) the height to which the ball climbed above the students hand
*March 12, 2012*

**Physics**

A car is doing a loop-the-loop. The loop has a radius of .4m. Assume the car is starting with the minimum speed it needs in order to stay in contact with the track at all times (at the top of the track, the car is not applying a force to the track). neglect friction. What is ...
*March 6, 2012*

**geometry**

60ft
*March 4, 2012*

**geometry**

120 ft
*March 4, 2012*

**college algebra**

A triangle is bounded by the x-and y-axes and must pass through P(2,2) a.) find the area of the triangle as a function of x (Hint: let C be the point (0,2) and D be the point (2,0). Use the fact that ACP and PDB are similar triangles.) b.) What is the domain of the function ...
*February 28, 2012*

**college algebra**

A piece of pottery is removed from a kiln and allowed to cool in a controlled environment. The temperature (in degrees Fahrenheit) of the pottery after it is removed from the kiln is shown for various times (in minutes) in the following table. Time(min) Temperature (F) 15 2200...
*February 28, 2012*

**college algebra**

A rectangle is bounded by the x-and y- axes and the graph of y = -1/2x + 4. a.) Find the area of the rectangle as a function of x. b.) Complete the following table x area 1 2 4 6 7 c.) What is the domain of this function?
*February 28, 2012*

**college algebra**

A magazine company had a profit of $98,000 per year when it had 32,000 subscribers. When it obtained 35,000 subscribers, it had a profit of $117,500. Assume that the profit P is a linear function of the number of subscribers s. a.) Find the function P b.) What will the profit ...
*February 28, 2012*

**college algebra**

Thank you and sorry someone impersonated you.
*February 28, 2012*

**college algebra**

sorry I will resubmit them. Thanks.
*February 28, 2012*

**college algebra**

yes
*February 28, 2012*

**physics**

If you were asked to design a capacitor in which small size and large capacitance were required, what factors would be important in your design?
*February 27, 2012*

**physics**

A river is moving at 4.0 m/s [s] , and a swimmer swims across it at 1.4 m/s [e] relative to the water. What is the swimmers velocity measure with respect to the river bank
*February 26, 2012*

**physics**

A river is moving at 4.0 m/s [s] , and a swimmer swims across it at 1.4 m/s [e] relative to the water. What is the swimmers velocity measure with respect to the river bank
*February 26, 2012*

**college algebra**

Given f(x)= 3x^2+x-30 and g(x)=x-3 find f(x)-g(x)
*February 24, 2012*

**college algebra**

Find the vertex for f(x)=-5x^2-6x=3
*February 23, 2012*

**economics**

An article in Business Week warned of the dangers of deflation as the collapse of numerous Asian economies was creating worries that Asia might try to “ export its way out of trouble” by oversupplying everything from automobiles to semiconductors. Evidence that ...
*February 21, 2012*

**Math**

A sensor light installed on the edge of a home can detect motion for a distance of 50ft. in front and with a range of motion of 192degree. Over what area will the sensor detect motion and become illuminated?
*February 20, 2012*

**math**

B=1.69 (sqrt (s)+4.45)-3.49 solve for s
*February 16, 2012*

**Math**

4t+14=6t/5+7
*February 16, 2012*

**Physics!! Help!!!!!**

A wire of length L and cross-sectional area A has resistance R. What will be the resistance R_stretched of the wire if it is stretched to twice its original length? Assume that the density and resistivity of the material do not change when the wire is stretched. Express your ...
*February 15, 2012*

**algrebra**

16(5/8x+1/16)x=16(7/16+x) I have no idea how to multiple 5/8 by 16
*February 8, 2012*

**chemistry **

who was the first scientist to identify a nuclear bombardment reaction?
*February 8, 2012*

**Physics!! Help!!!!!**

. A neutral conducting sphere contains a spherical cavity. A point charge +q is located at the |center of the cavity. A. What is the total surface charge on the interior surface of the conductor? B. What is the total charge on the exterior surface of the conductor?
*February 3, 2012*

**math**

the top will have a piece of marble 20 1/2 by 22 bordered by 3 1/4 inches of wood on all four sides. Give the overall dimension of the table top
*February 2, 2012*

**physics**

The angle between the polarizer transmission axis and the plane of polarization of the incoming light is 30 +/- 2 deg. If the incident light intensity Io is 100 W/cm2 what would be the intensity I after the light is transmitted through the polarizer? What would be the percent ...
*January 27, 2012*

**Precalculus**

Consider the equation 7sin^2x - (4sin2^x)/cosx = -1 a) Put the equation in standard quadratic trig equation form. Why is it 7sin^2x - 8sinx + 1 =0?
*January 27, 2012*

**Precalculus**

Which of the following is a solution for the equation 1/485tan^2x = 0? a) pi b) pi/2 c) 485pi d) no solution Which of the following is NOT a solution to the equation 4sin^2x = 1 for 0≤x≤2pi? a) 30 degrees b) 210 degrees c) 150 degrees d) 120 degrees?
*January 27, 2012*

**Precalculus**

Solve the equation (x+3)(x-3) = -9. What are the solutions to the equation if you replace x first with sinx and then with cosx, where 0≤x≤2pi?
*January 26, 2012*

**Precalculus**

Thank you!
*January 26, 2012*

**Precalculus**

Thank you~ May I know how you got 150 degrees? I am so confused when finding the reference angles, whether to subtract or add the degrees.
*January 26, 2012*

**Precalculus**

Sorry, I meant 2sinx - cos^2x = sin^2x for 0 ≤ x ≤ 2π 2sinx - cos^2x = sin^2x Do I change the left side to 2sinxcosx - cos^2x = sin^2x
*January 26, 2012*

**Precalculus**

Determine the solutions to the equation 2sinx − cos2x = sin2x for 0 ≤ x ≤ 2π . How do I start this question?
*January 26, 2012*

**Math**

How can I figure out what the line segment of radical, or Sq root of 17 looks like?
*January 18, 2012*

**Physic**

A cheetah can accelerate at a rate of 8.0 M/S^2. Assuming it starts from rest, what will its velocity be after 3.5 SECONDS?
*January 14, 2012*