# Posts by Quidditch

Total # Posts: 512

1. You are correct!
2. Where is the energy stored in a flashlight?
3. I think that the semicolon (;) should be deleted in your line: if (a == b) System.out.println(a*b);
4. You are correct!
5. Yes, you got it! 49 = 49
6. No, D is not correct. (7*7*7*7)=? (7*7)=? Divide the 4 7s multiplied by the 2 7s. What do you get
7. What did you get when you calculated 7^4/7^2
8. You're welcome!
9. Yes, you got it! 5^0=1
10. You are correct on 1. The answer is c. You are not correct on 2.
11. What did you get when you converted the weight to kg?
12. Correct!
13. oops... I meant amps.
14. Your are correct! current for 40 volts across 12 ohms: 40V/12 ohms=3.33 smps
15. 2.5 times \$4.00 is the cost to make 1 tent. So, what would it cost to make 4 tents?
16. The first equation has y=10-2.2x Substituting that value for y into the second equation: 5x + (10-2.2x)=70 5x + 10-2.2x=70 combining... 2.8x=60 x=? Plug that value for x into the first equation to find y.
17. When you multiplied the second equation by 2 your result is wrong. It should be: 6x + 12y=52 NOT: 6x-12y=52
18. 30% of 200,000 is NOT 6000
19. Looks good!
20. Try multiplying by a/a.
21. Don't forget to think about negative numbers here. What negative numbers would give you a correct answer?
23. Looks good!
24. You have the right idea. one revolution is 2(pi) radians. Converting revolutions to radians: R=revolutions Revolutions in Radians=R*2(pi) So, to convert 2.8 revolutions/sec to radians =2.8(2)(pi)/sec
25. With the values given, I did not find any of the answers on the graph. For a distance vs time graph. X axis is time and Y axis is distance. at t=6s, dist=5m at t=8s, dist=6m at t=10s, dist=7m at t=12s, dist=8m I don't see any of those as choices.
26. For problem 2, I got A, x=-1.
27. C is the answer I got.
28. Problem 1. Look at my calculation, the average rate is +12,not a negative number.
29. For a distance vs time graph. X axis is time and Y axis is distance. at t=6s, dist=5m at t=8s, dist=6m at t=10s, dist=7m at t=12s, dist=8m I don't see any of those as choices.
30. Problem 1 A is not the answer. f(4)- f(1) =11 - (-1) = +12 -------------- Problem 3. C looks correct
31. Problem 2. The answer is not B, (x=0).
32. Problem 1. The answer is NOT D. The average rate of change is: for x=1, f(1)=-3 for x=4, f(4)=-3 Average rate of change is 0, not a negative number. One of the answers does give a negative average rate of change.
33. Yes, that's what I got, also.
34. That's correct!
35. Let B = the "break even" number of books. Production costs=\$76,322 + B * \$10 Total Sales = B * \$25.50 Setting these equal... Total sales = Production costs or... \$76,322 + B * \$10 = B * \$25.50 Solve for B
36. 1, 2, 3, 4, and 6 look OK I don't understand 5, 7 is wrong.
37. number 4 should be +5 6 is wrong.
38. slope = rise/run. For a slop of 0.4 0.4 = rise/130 Solve for rise. It looks like you have accidentally moved the decimal in your line: .040=rise
39. Let D = the number of dimes. So, D + 9 = the number of nickels. Adding... D * 10 + (D + 9) * 5=135 combining 15 * D + 45 = 135 15 * D = 90 Divide both sides by 15 D = 6 There are six dimes. So, the number of nickels is 6 + 9 = 15
40. The time is takes to slow down is T2 - T1. That is given as 3.0s.
41. The best way to check is to substitute your answer back into the equation. SQRT(2x+1)-5=8 SQRT( (2*84)+1)-5=8 SQRT(168+1)-5=8 SQRT(169)-5=8 13 - 5 = 8 8 = 8 You are correct!
42. Adding the items gives \$460 The tax on that at 5.5% =0.055*\$460 =? Add the tax to the cost of the items. That value is one of the choices given.
43. -5+2*SQR(12) =-5+2*SQR(4*3) =-5+2*SQR(4)*SQR(3) =-5+2*2*SQR(3) =-5+4*SQR(3)
44. My Alt+251 keyboard did not post as a square root--reposting...
45. You got the right answer! It just needed to be reduced. -5 + 2*ã(12) =-5+2*ã(4*3) =-5+2*ã4 * ã3 =-5+2*2*ã3 =-5+4*ã3
47. Using that... Y=14.47m/s(2.2s)-(1/2)(9.8m/s)(2.2)^2 Y=31.834m - 23.716m =8.118m So it clears the wall by 8.118m - 6.7m =1.418m
48. I get 14.47m/s for Vy.
49. I calculated the ball was thrown at a speed of 18.12m/s. Vx is 24m/2.2s=10.91m/s Vx=V(cos(53)) That gives V as 18.12m/s
50. Sorry, I see that was given.
51. On part b, You need to find how long it takes the ball to go th 24.0m in the x direction. Use that time for the y calculation.
52. I believe Capreeca is wrong on this one. 2x+1=3 2x=2 x=1
54. Change the 31% to a decimal value. Then multiply both sides of the equation by Q. Then get all the Q terms on one side and the number terms on the other side. Combine the terms and solve for Q.
55. I think you made an error in adding the angles. In your problem angles are x, 3x, and 4x. Adding those gives 8x not 7x. Does that help?
56. let J=Jim's age let D=Dave's age It is given that Dave can vote. So D>=18 Dave is 5 years older J+5=D or J=D-5 Jim can't vote. J<18 Substitute for Jim's age: D-5<18 Solve this for the upper limit for Dave's age.
57. Sorry the next to last line should say to express LENGTH as a function of W. Then, solve for W.
58. What does the problem say: Perimeter is less than 48ft. Let P=perimeter Let L=length Let W=width P<48ft Express perimeter in terms of length and width: P=L+W+L+W or L+W+L+W<48ft Express the width as a funtion of L. Substitute that value into the above equation and solve ...
59. Yes, that is correct. I would really encourage you to carry the units through from start to finish. It seems like extra work, but it can help detect errors.
60. Yes, you are correct!
61. type LCM, least common multiple
62. I think 72 is the LCM, least common multile, not GCF, greatest common factor.
63. Add 4 to both sides. Then, square both sides. Does that help?
64. To clarify: (-4)^4 is not equal to -256.
65. -256 is not the correct answer.
66. Yes! All answers are correct. Note that answer 4 could be reduced to 19/30 hours.
68. Correcting typo The line 5 = H = 1 shoud read: 5 = H - 1
69. My error I just reread that the first 1/2 hour is included. I am quite sure that the it is \$30 for each additional 1/2 hour the equation is: Let H = the number of HALF HOURS \$200 = \$50 + (H-1))\$30 similarly \$150 = (H-1)*\$30 5 = H=1 adding 1 to each side: H= 6 This is the ...
70. I think there is some confusion here. Let H = the total hours \$200 = \$50 + (H-1)*\$30 Remember that the first hour is included in the \$50. subtract \$50 from both sides \$150 = (H-1)*\$30 divide both sides by \$30 5 = H -1 add 1 to both sides: H = ??
71. You are very welcome.
72. You're welcome, but I am not sure what you mean by reverse FOIL. First terms: x and x Outer terms: x and -5/4 Inner terms: -5/4 and x Last terms : -5/4 and -5/4 I just want to be sure you have a good understanding about the order.
73. OK, (x-5/4)^2 = (x-5/4)(x-5/4) multiplying (remember FOIL--first, outer, inner, last) = x^2 -(5/4)(x) - (5/4)(x) + (5/4)^2 = x^2 - (10/4)(x) + (5^2)/(4^2) = x^2 -(5/2)(x) + (25)/(16) Does that help?
74. Which side (left or right) is puzzling?
75. Be careful of units. You expressed the runway length in m (meters), but the takeoff speed is expressed in mi/h (miles/hour). You will need to do some units conversion.
76. Modern PCs have a word size of 32 or 64 bits. Early IBM PCs used an Intel 8088 which had an 8 bit data path.
77. my misspelling... You have AN eror.
78. You have and error. 3X + 240 + 36X = 6 39X = -234 X = ?
79. You are very welcome!
80. Since the moments were calculated from the end the fisherman is holding in his left hand, that force does not generate any moment.
81. Assuming the fishing pole is horizontal... Yes, the fisherman's left hand is exerting a downward force. You are correct.
82. You're welcome. Glad to help
83. 6 is correct. However, your last step is not quite correct. starting with... 20x + 10 - 10 = 130 - 10 20x = 120 Now divide both sides by 20, not 20x 20x/20 = 120/20 x = 6
84. Yes, that answer is correct.
85. You are headed in the right direction. That is a distance formula when there is uniform acceleration which is gravity in this problem. The formula is: s2 = s1 + vt + (1/2)(a)t^2 where: s2 = final distance s1 = initial distance v = initial velocity a = acceleration t = total ...
86. How are you solving it? What answer are you getting?