Thursday

September 3, 2015
Total # Posts: 637

**Physics**

what distance should you keep between you and the car in front of you if the traffic is moving at 65mph? Your reaction time is 1s, and both the cars can decelerate at the same rate. Include reasonable estimate for the length of the car (you don't want your bumper to end up...
*October 15, 2007*

**physics**

A football is kicked at 37degrees to the horizontal and it goes a distance of 98 yd. Ignore air resistance. a) what is the ball’s initial velocity? b) what is the vertical component of the ball’s velocity? c) what is the horizontal component of the ball’s ...
*October 15, 2007*

**physics**

Can an object's velocity change direction when its acceleration is constant? a) No this is not possible because it is always speeding up b) No this is not possible because it is always speeding up or always slowing down, but it can never turn around c) Yes it is possible ...
*October 15, 2007*

**physics**

what distance should you keep between you and the car in front of you if the traffic is moving at 65mph? Your reaction time is 1s, and both the cars can decelerate at the same rate. Include reasonable estimate for the length of the car (you don't want your bumper to end up...
*October 15, 2007*

**physics**

Which of the following statements is not true? a)the horizontal component of velocity cannot be larger than the total velocity b)the vertical component of velocity cannot be larger than the total velocity c)Neither horizontal nor vertical components of velocity cannot be ...
*October 15, 2007*

**physics**

A car is moving with constant velocity. Which of the following is true? a) the car travels the same distance in each second b) car's velocity increases by the same amount in each second c)car's velocity decreases by the same amount in each second d)car's velocity ...
*October 15, 2007*

**physics**

A car is moving with constant acceleration. Which of the following is true? a) the car travels the same distance in each second b) car's velocity increases by the same amount in each second c)car's velocity decreases by the same amount in each second d)car's ...
*October 15, 2007*

**physics**

when lightning strikes you can see it at a speed of 3x10^8m/s. But you hear thunder at about 340m/s in 70 degrees air temperature. a) If you are a mile away from lightning, how long of a delay is there? b) if the delay between the lightning and thunder were 1s how far away ...
*October 15, 2007*

**Physics**

You are sitting in your car at a traffic light at the foot of a 200 ft long ramp that will take you onto the interstate. If your cat can at best accelerate at 5 m/s^2 and the traffic on the interstate is moving at 65mph. will the ramp be long enough for you to reach that speed...
*October 15, 2007*

**Math riddle**

Ok, this is driving me crazy .Grandpa Grumps had just informed the local police that several children were rollerblading in his driveway. However, by the time Police Officer Nickham turned up, the children had gone and Grandpa Grumps couldn’t remember their faces. So ...
*October 12, 2007*

**Physics**

during a hockey game a puck of mass .3 kg is given an inital speed of 12m/s. it slides 50 m o the ice before stopping. Assume the puck decelerates at a constant rate. what is the coefficient of friction betweent the puck and the ice? I know that it would be a very small answer...
*October 10, 2007*

**Physics**

you lift a 10 N physics book up in the air a distance of 1m at a constant velocity of .5m/s. What is the work done by the weight of the book? a) +10 J b)-10 J c) +5 J d)-5 J 10 N is the force of gravity and to find work you do this: W=F_g(change in distance) (10N)(1m)= +10J so...
*October 10, 2007*

**Physics**

a packing ccrate slides down an incline ramp at constant velocity. Thus we can deduce that a) a frictional force is acting on it b) a net downward force is acting on it c) it may be accelerating d) it is not acted on by appreciable gravitational force with a constant velocity ...
*October 10, 2007*

**Physics**

A wooden block slides directly down an incline plane at a constant velocity of 6 m/s. What is the coefficient of kinetic friction if the plane makes an angle of 30 degrees with the horizontal? the coefficient of kinetic friction = force of kinetic friction/normal force. How ...
*October 10, 2007*

**Algebra II**

Bolivian coffee sells for $4.59 per pound, and Columbian coffee sells for $5.95 per pound. How many pounds of each coffee should be mixed to produce 4000 pounds of a mixture that will be sold for $5.10 per pound? I think this is a system of equations but I'm not sure. If ...
*October 7, 2007*

**Chemistry- To Bob Pursleyy**

Thank you sooo much, I was using grams of Molybdenum, so I looked up the mass of an electron and converted it and got the correct answer. I thought I didn't solve for V right, I'm amazed that I got that right. Thank you for your help!
*October 7, 2007*

**Chemistry- To Bob Pursleyy**

I am having a hard time on how to get V in wavelength= h/mv If I multiply by mv then I get W(mv)=h Then I get Wmv=h I divide by Wm and get V=h/Wm ...but that doesn't seem to work. My other question is if I am using the correct values. W (wavelength or lamda)= 7.11x10^(-11)...
*October 7, 2007*

**Chemistry**

Under appropriate conditions, molybdenum emits X rays that have a characteristis wavelength of 0.711 Angstrom. These X rays are used in diffraction experiments to dtermine the structures of molecules. How fast would an electron have to be moving in order to have the same ...
*October 7, 2007*

**Vocabulary**

I have gotten help from here before and I was hoping that another kind person could help me again, since I always get such helpful answers. I have written an essay and I have my ideas stated pretty well but I am adding the final touches to it. This include spicing up the words...
*October 6, 2007*

**Physics**

A .5kg ball hangs on a string attached to the ceiling. If the string is cut what forces act on the ball as it falls? Ignoring air resistance. Weight is one of the forces acting on the ball. Is there another force acting on the ball? I know there isn't tension, friction. Is...
*October 3, 2007*

**Physics**

Two books of masses m1=10kg and m2= 20kg are connected by a rope. The horizontal force on the more massive box is 900 N. Assume there's no friction. a) what is the acceleration of the more massive box b) Acclereration of the less massive box a) f=ma 900=20a a=45m/s^2 b) f=...
*October 3, 2007*

**Physics**

An example of a force which acts at a distance is a) tension b) weight c) friction d) normal force Isn't the answer c) the further an object goes the more resistance?
*October 3, 2007*

**Physics**

A stack of books rests on a level perfectly smooth surface. A force F acts on the stack and it acclerated at 3m/s^2. A 1kg book is added to the stack. The same force is applied and now the stack accelerates at 2m/s^2. What was the mass of the original stack? I think i would ...
*October 3, 2007*

**Physics**

A stone is thrown straight up. At the top of the path, the net force acting on it is (ignore air resistance) a) greater than its weight b) greater than zero, but less than its weight c) instantaneously equal to zero d) equal to its weight At the very top of the path wouldn'...
*October 3, 2007*

**Physics**

A constant net force acts on an object. Describe the motion of the object. a) constant acceleration b) constant speed c) constant velocity d) increasing acceleration I believe the answer would be a) constant acceleration. Given F=ma. Is this correct?
*October 3, 2007*

**Chemistry**

Unfortunately I was hit by the sweep of illnesses going around due to changing whether and missed school today. Thus I missed the notes in Chemistry leaving me completely confuzzled about tonights homework on Dimmensional analysis or Unit Factoring. I called a friend but she ...
*October 1, 2007*

**college class**

Consider the choices of Native Americans who decide to stay on their tribe's native land or reservation, and those who choose to relocate to a city. If you were presented with this decision, which would you choose and why? Please be sure to fully explain your answer in a ...
*September 30, 2007*

**Physics**

A projectile is launched from ground level with an inital velocity of 50 m/s at an angel of 60 degreess aove the horizontal. Use g=10m/s. What is the max height reached by the projectile? I used change in y=voyt +1/2at^2 =50(2.4) + 1/2(=10) (2.5)^2 =125-31.25 =93.75m I was ...
*September 26, 2007*

**Physics**

When a football in a field goal attemp reaches its max height how does its speed compare to its inital speed? a)it's zero b) it is less than its inital speed c)it is equal to its inital speed d)it is greater than its inital speed since at the max height v=0 isn't the ...
*September 26, 2007*

**Physics**

a ball thrown horizontally from a point 40m above the ground,strikes the ground after traveling a distance of 9m. with what speed was it thrown? use g=10m/s^2 first i need to find the time so I used y=y_0 +v_0t +1/2at^2 -40=-1/2(10)t^2 t=8s then x=x_o+vt 9=v(8) v=1.125m/s Is ...
*September 26, 2007*

**Physics**

A projectile is shot horizontally at 30m/s from the roof of a building 100m tall. Use g=10m/s^2. Choose + vertical direction to be pwards. a) determine the time necessary fot the projectile to reach the ground below b) determine the horizontal distance from the base of teh ...
*September 26, 2007*

**Physics**

A jumper in the long-jump goes into the jump with a speed of 10m/s at an angle of 30 degrees above the horizontal. Use g=10m/s. a) how long in the air is the jumper before returning to the Earth? b) How far does the jumper jump? for a) I got .001s as the answer which logically...
*September 26, 2007*

**Physics**

A plane flying horizontally at a speed of 50m/s and at an elevation of 160m drops a package. two seconds later it drops a second package. How far apart will the two packages land on the ground? a)100m b)162m c)177m d)283m i think the answer is a) I got 150m for the first ...
*September 25, 2007*

**Physics**

When a football in a field goal attemp reaches its max height how does its speed compare to its inital speed? a)it's zero b) it is less than its inital speed c)it is equal to its inital speed d)it is greater than its inital speed since at the max height v=0 isn't the ...
*September 25, 2007*

**Physics**

A jumper in the long-jump goes into the jump with a speed of 10m/s at an angle of 30 degrees above the horizontal. Use g=10m/s. a) how long in the air is the jumper before returning to the Earth? b) How far does the jumper jump? for a) I got .001s as the answer which logically...
*September 25, 2007*

**Physics**

A projectile is shot horizontally at 30m/s from the roof of a building 100m tall. Use g=10m/s^2. Choose + vertical direction to be pwards. a) determine the time necessary fot the projectile to reach the ground below b) determine the horizontal distance from the base of teh ...
*September 25, 2007*

**Physics**

A projectile is shot horizontally at 30m/s from the roof of a building 100m tall. Use g=10m/s^2. Choose + vertical direction to be pwards. a) determine the time necessary fot the projectile to reach the ground below b) determine the horizontal distance from the base of teh ...
*September 25, 2007*

**Physics**

"from zero to sixty in 8 seconds" is a description of: a) average speed b) instantaneous speed c)average acceleration d) instantaneous acceleration I know for sure that a) and c) aren't the right answers since average is over a long time period or the whole trip...
*September 21, 2007*

**Physics**

Suppose that a car traveling to the West (-x direction) begins to slow down as it approaches a traffic light. make a statement concerning its acceleration. a) the car is decelerating and its acceleration is positive b)the car is decelerating and its acceleration is negative c...
*September 21, 2007*

**Physics**

A car starts from rest and accelerates at 5m/s^2 for 4s, then maintains that velocity for 3 seconds and then decelerates to a rate of 2m/s^2 for 3 seconds. How far does the car travel? I would have to add the total distance throughout the trip. And to find the distance I would...
*September 21, 2007*

**Physics**

On a postition versus time graph to find the acceleration you would simply find the area under the graph right? and how would you figure out whether acceleration is increasing, decreasing, constant of unknown from a graph? My guess is that the accereration is constant throughout.
*September 21, 2007*

**Physics**

A small mailbag is releassed from a helicopter that is ascending steadily at 5m/s. After 2s. a) what is the speed of the mailbag? b) how far is it below the helicopter? a) would I use v=v_0 +at v=5m/s + 9.8m/s^2(2s) v=24.6 m/s is this the correct speed of the mailbag? For b) i...
*September 19, 2007*

**Physics**

Killer whales at Sea Worl routinely jump 8 m above the water. What is their speed as they leave the water to achieve this? I know that h=8m v=? Would I use h=h_0 + v_0t = 1/2 at^2 but the problem would be that I also don't know the time. I am confused about which equation ...
*September 19, 2007*

**Physics**

Three vectors, each have a magnitude of 30 units, have their tails at the same oint and are directed 120 degrees from each other. Make a statement concerning the sum of these three vectors. a) the sum vector is 0 b) the sum vector is greater thatn 30 c) the sum vector is equal...
*September 19, 2007*

**Physics**

The sum of 2 vectors is the smallest when the angle between them is : a) 0 b) 45 c) 90 d) 180 d) i believe is the correct answer but i'm not sure exactly. Thanks in advance for your help.
*September 19, 2007*

**Physics**

Which of the following is an accurate statement? a) a vector cannot have zero magnitude if one of its components is not zero b) the magnitude of a vector can be less than the magnitude of one of its componenets c) if the magnitude of vector A is less than the magnitude of ...
*September 19, 2007*

**inb-check this please**

thank you
*September 13, 2007*

**inb-check this please**

Developed country partners in countertrade contracts have had problems with quality and timely delivery of goods from the developing country partners. How are they trying to deal with those problems? 1999, 12 of the 15 European Union (EU) member-countries agreed to begin a ...
*September 13, 2007*

**inb**

Developed country partners in countertrade contracts have had problems with quality and timely delivery of goods from the developing country partners. How are they trying to deal with those problems?
*September 13, 2007*

**Physics**

A car starts from rest and undergoes uniform acceleration. During the first second it travels 6 m. a) what is the car's acceleration? b) How far will the car travel during the third second? For a) I used v= v_0 +at 6=0 a*1 so a= 6m/s^2 For b) I used d=vt d=6(3) = 18 m Did ...
*September 12, 2007*

**Physics**

A car starts from rest and accelerates at 5 m/s^2 for 4 s, then maintains that velocity for 3 seconds, then decelerates at the rate of 2m/s^2 for 3 seconds. a) what is the final speed of the car? b) how far does the car travel? a) v = v_0 +at = 0+5(4)= 20m/s =0+5(3)= 15m/s =0+...
*September 12, 2007*

**Physics**

You are driving home on a weekend from school at 65mph for 130 miles. It then starts to snow and you slow to 45 mph. You arrive home after driving 4 hours. How far is your hometown from school? First I found the time with d/v=t so 130/65= 2 hours I used d= d_0 +vt =130 +45(6...
*September 12, 2007*

**Physics**

A car with good tires on a dry road can decelerate at about 5 m/s^2 when breaking. Suppose a car is initially traveling at 65 mph. What is the stopping distance?(give answer in meters and in feet) I changed 65mph into 29.05m/s. so I would use d-d_0 = (v^2 -v_0^2)/2a and when I...
*September 12, 2007*

**Physics**

You are driving home on a weekend from school at 65mph for 130 miles. It then starts to snow and you slow to 45 mph. You arrive home after driving 4 hours. How far is your hometown from school? First I found the time with d/v=t so 130/65= 2 hours Then I used d= (v-v_0)/(t-t_0...
*September 11, 2007*

**Physics**

A car starts from rest and accelerates at 5 m/s^2 for 4 s, then maintains that velocity for 3 seconds, then decelerates at the rate of 2m/s^2 for 3 seconds. a) what is the final speed of the car? b) how far does the car travel? a) v = v_0 +at =0+2(3)= 6m/s Would I use the part...
*September 11, 2007*

**Physics**

A car starts from rest and undergoes uniform acceleration. During the first second it travels 6 m. a) what is the car's acceleration? b) How far will the car travel during the third second? For a) I used v= v_0 +at 6=0 a*1 so a= 6m/s^2 For b) I used d=d_0 +v_0t + 1/2 at^2...
*September 11, 2007*

**Physics**

If you are driving at 65mph along a straight road and you look to the side for 2 seconds, how far do you travel during this inattentive period? (Give the answer in meters and in feet) Would i use d= d_0 + vt to solve this problem or would I use another equation? When i used ...
*September 11, 2007*

**Physics**

Suppose that an object travels from one point in space to another. Make a comparison between the displacement and the distance traveled. a) the displacement is either greater than or equal to the distance traveled b)the displacement is always equal to the distance traveled. c)...
*September 9, 2007*

**Physics**

When is the average velocity of an object equal to the instantaneous velocity? a) always b)never c) only when velocity is constant d)only when velocity is increasing at a constant rate c) would be the answer since you could cross out a). I do know that instantaneous velocity ...
*September 9, 2007*

**Physics**

a car manufacture advertise that a car goes "from zero to sixty in 8 seconds" is a description of: a) average speed b) instantaneous speed c) average velocity d) instantaneous acceleration a) and b) are incorrect since it's a change in velocity, whcih means it&#...
*September 9, 2007*

**science**

Object A and B both start at rest. They both accelerate at the same rate. However , object A accelerates for twice teh time as object B. What is the distance traveled by object A compared to that of object B? a) the same distance B) twice as far c) three times as far d) four ...
*September 6, 2007*

**science**

a car manufacture advertise that a car goes "from zero to sixty in 8 seconds" is a description of: a) average speed b) instantaneous speed c) average velocity d) instantaneous acceleration a) and b) are incorrect since it's a change in velocity, whcih means it&#...
*September 6, 2007*

**science**

When is the average velocity of an object equal to the instantaneous velocity? a) always b)never c) only when velocity is constant d)only when velocity is increasing at a constant rate c) would be the answer since you could cross out a). I do know that instantaneous velocity ...
*September 6, 2007*

**science**

Suppose that an object travels from one point in space to another. Make a comparison between the displacement and the distance traveled. a) the displacement is either greater than or equal to the distance traveled b)the displacement is always equal to the distance traveled. c)...
*September 6, 2007*

**science**

An average human heart rate is 70 beats per minute. How many times it beats over 70 year lifetime? use scientific notation. 365 = the number of days in a year 70 years /1 * 365 days / year = 25,550 25,550/1 * 24 hours/ day = 613,200 613,200/1 * 60 minutes/ hour =36,792,000 70 ...
*September 2, 2007*

**Precalculus**

Write the statement using absolute value notaion: The distance between x and 1 is 7. I got the answer as the absolute value of x, plus 7 equals 1 Is that correct?
*August 29, 2007*

**Conversion**

How many cubic millimeters are there in one square centimeter? I know that in one square centimeter there is 100 millimeters squared. So this is what I did: x^3 = 100^2 so x=100 is this correct?
*August 29, 2007*

**Algebra**

I think that the goal is to get rid of the 5th root in this case. I know that I have to make whatever is under or in the root -in this case the number is X equal some number to the fifth power. I am supposed to use the rule a^(m/n)= n (the n-root) (don't know how to type ...
*July 24, 2007*

**Algebra**

Please read and then help me! (x^(-3/5)) ----------- divide x ^ (1/5) I know the problem then needs to look like this: (x^(-3/5))(x^(-1/5)) (multiply the two above) Then it needs to look like this: (I can't write it though, so I'll tell you) The 5th root out of (x^(-3...
*July 24, 2007*

**Rational Expressions Algebra**

Electronics The electrical resistance (r) of a cable varies directly (y=kx) as its length (l) and inversely (y= k/x) as the square of its diaeter (d). If a cable 16,000 ft long and 1/4 in. in diameter has a resistance of 3.2 ohms, what is the resistance of a cable that is ...
*July 21, 2007*

**Algebra**

Simplify [(1)-(1/x+2)] / [(1)- (3/x+4)] I know I need to find the LMC here, and the answer is (x+4)/(x+2) but I do not know how to get to the answer and how to use the LMC. I need help! You need to use more parentheses to distiguish (1/x)+ 2 from 1/(x+2), and (3/x)+4 from 3/(x...
*July 21, 2007*

**algebra**

Solve Q=(n-s)/n for n To get you started, multiply both sides by n and go from there. Post your work if you get stuck AND tell us what you don't understand about the next step.
*July 19, 2007*

**Algebra**

(3x+4)/(3x-4)+(3x-4)/(3x+4) --------------------------- Divide top by bottom (3x-4)/(3x+4)-(3x+4)/(3x-4) Very Big Problem and help would be greatly appreciated not that tough once you notice that your question has the pattern (a/b + b/a)÷(b/a - a/b) where a = 3x+4 and b...
*July 19, 2007*

**math**

describe an application for the use of ratios or portions. And describe how an application problem could be useful in daily life? Lok at the post directly below yours. I think it will serve as an example.
*May 22, 2007*

**International business**

I need help with finding a potential market and product to get my export operations started. I need a 15to20 PowerPoint presentation with detailed speakers notes that analyze a potential international business opportunity. Thank you for using the Jiskha Homework Help Forum. ...
*May 14, 2007*

**Chemistry**

The solubility of KCLO3 at 25 degree celcius is 10.9 per 100.g of h20. question: If 15 g are addded to 100 g of water at 25 degree celcius with stirring, how much of KCLO3 will dissolve? Is the solution saturated, unsaturated, or supersaturated? please help me with this ...
*May 7, 2007*

**calculus**

First I would find the first derivative which is the slope and then would I plug in the given value into the original equation to find y and then use y-y_1=m(x-x_1)? Find the euation of the tangent line at the given value a) y=ln abs(x+4) x = -3 b) y= (x^2 +5)/(x+1) x=1 a) I ...
*May 2, 2007*

**Calc**

intergral of (x^3 -4x + 3)/(2x) dx would this be ln abs(x^3-4x+3) + C? I don't really understand how to solve this problem. d/dx (tan (x^2)) sec^2(x^2)(2x) would this be the correct answer to find the derivative of tan (x^2)? no, because if you differentiate your answer ...
*May 2, 2007*

**Calc**

Find the derivative of a) y=cos (x/2) b) yx-3x^2 +6 = y^4 + x a) -sin (x/2)(2+x)/2^2 -sin(x/2)(x/2) b) x dy/dx + y - 6x = 4y^3 dy/dx + 3x^2 dy/dx (x -4 y^3) = 3x^2 -y +6x dy/dx = (3x^2 -y +6x)/(x -4 y^3) I used inplicit differation for part b are these correct? Thanks for your...
*May 2, 2007*

**algebra**

i am supose to graph this using three points on a graph how am i suppose to find three points for this problem x<=2 What about x=2, y = anything; x=1, y= anything; and x=-4, y= anything. I would write as as x+y<=2 2+y<=2 then solve for y to get my points
*May 2, 2007*

**algebra word problem**

A small company produces both dollhouses and sets of doll furniture. The dollhouses take 3 hours of labor to produce, and the furniture sets take 8 hours. The labor available is limited to 400 hours per week, and the total production capacity is 100 items per week. Existing ...
*May 1, 2007*

**math word problems**

The sum of two numbers is 69. The second is 9 more than 4 times the first. What are the two numbers? would the equation i have be right 4x+y+9=69 4*15+0+9=69 60+9=69 couldn't it also be: 4x+y+9=69 4*14+4+9=69?
*April 27, 2007*

**math word problems**

The sum of two numbers is 69. The second is 9 more than 4 times the first. What are the two numbers? would the equation i have be right 4x+y+9=69 4*15+0+9=69 60+9=69 No. Let the two numbers be x and y, with x the smaller number. x + y = 69 y = 4x + 9 5x + 9 = 69 x = 12 Use any...
*April 27, 2007*

**algebra**

Solve the system by graphing. x + y = 4 –x + y = 2 confused where do i start do i need to solve for x and find points I'll bet that after doing a few like this you would be able to do this one in your head. just add then up. The x's will cancel and you will have ...
*April 27, 2007*

**ALGEBRA**

Find all positive values for k for which each of the following can be factored. I have 2 problems i think i got the one right but not sure the second one i have no idea where to even start 2x^3+16x^2-40x=2x(x^2+8x-20) (x-2)(x+10)=8x this one i am stumped can some one explain ...
*April 25, 2007*

**math**

For the universal set U= {0,1,2,3,4,5,6,7} And the sets A={1,5}, B={1,2,3,4} And C= {4, 6} lists the elements in the following Sets. a. A ¢¯ B b. A U Bf c. A ¢¯(B U C) d. C ¢¯ (B ¢¯ A)f U means: state ...
*April 18, 2007*

**math**

I need help with slopes and lines. Determine the slope of each line a line through points (-1, 2) and (2, -7) Slope of a line through two points (x1, y1) and (x2, y2) is (y2 - y1)/(x2 - x1). So substituting the given points we have (-7 - 2)/(2 - (-1)) i.e -9/3 = 3 Oops. it ...
*April 18, 2007*

**english**

can someone help me correct it Is consumerism taking over mens lives?
*April 17, 2007*

**Physics**

A force F is exerted by a broom handle on the head of the broom, which is of mass m. The handle is at angle theda to the horizontal. (where it's tilted towards the left at about 30 degrees to the horizonal). The work is: a)fdsin theda b)fdcos theda This would be b) right? ...
*March 26, 2007*

**Physics**

When a block slides a certain distance down an incline the work done by gravity is 300 J. What is the work done by gravity if this block slides the same distance up the incline? a) 300 J b) zero c) -300 J d) It cannot be determined without knowing the distance the block ...
*March 26, 2007*

**Physics**

A ball is tossed straight up from the surface of a small spherical asteroid with no atmosphere. The ball goes to a height ewual to the asteroid's radius and then falls straight down towardd the surface of the asteroid. What forces if any act on the ball while it is on the ...
*March 26, 2007*

**Physics**

F=kx k=100 x=.03 F=100*.03=3N (directed towards center b/c Centrip. force always does that)
*March 26, 2007*

**Physics**

A spring has a force constant of 100N/m and an unstretched lenght of .07 m. One end is attached to a post taht is free to rotate in the center of a smooth table. The other end is attatched to a 1 kg disc moving in uniform circular motion on the table, which stretches the ...
*March 26, 2007*

**Physics**

A wheel with rotational inertia I is mounted on a fixed, fricitonless axle. The angular speed w of the wheel is inccreased from zero to w_f in a time interval T. 1: What is the average net torque on the wheel during the time interval, T? a) w_f/T b)w_f/T^2 c) Iw_f^2/T d)Iw_f/T...
*March 25, 2007*

**Physics**

When a block slides a certain distance down an incline the work done by gravity is 300 J. What is the work done by gravity if this block slides the same distance up the incline? a) 300 J b) zero c) -300 J d) It cannot be determined without knowing the distance the block ...
*March 25, 2007*

**Physics**

To streatch a certain nonlinear spring by an amount 2x requires a force F given by F=40x-6x^2 where F is in newtons and x is in meters. What is the change in potential energy when the spring is stretched 2 meters from its equilibrium position? a)16 J b)28 J c)56 J d)64 J e)80 ...
*March 25, 2007*

**Physics**

A target lies flat on the ground 3m from the side of a building which is 10m tall. A student rolls a ball off the horicontal roof of the building in the direction of the target. Air resistance is negligible. Te horizonal speed with which the ball must leave the roof if it is ...
*March 25, 2007*

**Physics**

The velocity of a projectile at launch has a horizontal component v_h and a vertical component V_V. Air resistence is negligible. When the projectile is at the hightest point of its trajectory, which of the following show the vertical and horizontal components of its velocity ...
*March 25, 2007*

**Physics**

An ideal massless spring is fixed to the wall at one end. A block of mass M attached to the other end of the spring oscillates with amplitude A on a frictionless, horizontal surface. The maximum speed of the block is V_m. The force constant of the spring is a)Mg/A b)MgV_m/2A c...
*March 25, 2007*

**Physics**

A spring has a force constant of 100N/m and an unstretched lenght of .07 m. One end is attached to a post taht is free to rotate in the center of a smooth table. The other end is attatched to a 1 kg disc moving in uniform circular motion on the table, which stretches the ...
*March 25, 2007*