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April 20, 2014

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physics
if a motorboat travels at 25km/hr down a river whose velocity is 4km/hr wgat is the boats actual velocity? a. 21km/hr b. 29km/hr c. 100km/hr d. 6.2km/hr please repost the answer
Tuesday, March 18, 2008 at 2:11pm by michelle

HELP ON MATH PLEASE!!!!!!!
i would think first find the average of her running speed = 4 m/hr + 6 m/hr = 10 m/hr divided by 2 = an average of 5 m/hr now 5 m/hr = 1.25 hr 1.25 hr x 5 m/hr = 6.25 miles Hope that helps, the questions seems a little vague so thats why finding an average of her running ...
Wednesday, February 29, 2012 at 6:59pm by Rose Bud

Word problem
This is actually a multiple choice question and the choices are: a.)20/3 hr b.)2/13 hr c.)5/3 hr d.)1.5 hr Would the answer be c?
Saturday, October 11, 2008 at 8:58pm by Jennifer

Word problem
This is actually a multiple choice question and the choices are: a.)20/3 hr b.)2/13 hr c.)5/3 hr d.)1.5 hr Would the answer be c?
Saturday, October 11, 2008 at 8:58pm by Jennifer

science physics
The speed at which the two objects are approaching each other (from the trains' perspective) is 95 km/h (x 2) = 190 km/h. If they are 7.5 km apart at first, you can set up a proportion: 190 km 7.5 km ------ = --------- 1 hr x hr Cross-multiply the terms and set them equal to ...
Wednesday, October 6, 2010 at 11:25pm by Steven

SCIENCE(PHYSICS)
A train travels 40 km/hr for 0.2 hr, 50km/hr for next 0.2hr and 60km/hr for next 0.4 hr.calculate the average speed of train
Sunday, May 22, 2011 at 6:28am by YASH

math
MTθF: 6/5 hr Sat: 4/5 hr W 1/5 hr 4 * 6/5 + 4/5 + 1/5 = 29/5 = 5 4/5 hr
Friday, March 28, 2014 at 5:19pm by Steve

SCIENCE(PHYSICS)
A train travels 40 km/hr for 0.2 hr, 50km/hr for next 0.2hr and 60km/hr for next 0.4 hr.calculate the average speed of train. PLEASE SOLVE THE QUESTION WITH ANSWER AS I WAS NOT ABLE TO GET THE ANSWER
Monday, May 23, 2011 at 2:49am by YASH

SCIENCE(PHYSICS)
A train travels 40 km/hr for 0.2 hr, 50km/hr for next 0.2hr and 60km/hr for next 0.4 hr.calculate the average speed of train. My Solution:-1st hr. distance=40 multiplied by 0.2=8km 2nd hr.= 50 multiplied by 0.2=10km 3rd hr. =60 multiplied by 0.4=24 km Average speed=10+24+8 ...
Wednesday, May 25, 2011 at 6:35am by YASH

Intergated chemistry/physics
acceleration = (Change in velocity) / (time in hours) 4sec / (3600sec/hr) = 0.0011111 hour accel = (99.2km/hr) / (0.0011111 hr)=89286km/hr^2
Wednesday, October 3, 2012 at 11:01am by GeorgeK

Math
distanceCarrie=3mi/hr*time distanceCrystal=9mi/hr*(time-1/3) 20 min is 1/3 of an hr... set them equal 3t=9t-3 t= 1/2 hr now you can figure the distance from the first equation.
Saturday, March 20, 2010 at 10:04am by bobpursley

math
First, convert minutes to hours: 5 min*(1 hr/60 min)=0.0833333...hr or 1/12 hr Then multiply it to 24 miles/hr: (24 miles/hr) * (1/12 hr) = 2 miles.
Thursday, September 30, 2010 at 8:28pm by Brianna

Calculus
The percentage of alcohol in a person's bloodstream t hr after drinking 8 fluid oz of whiskey is given by the following equation. A(t) = 0.26te-0.3t , (0 t 12) (a) What is the percentage of alcohol in a person's bloodstream after 1/2 hr? After 6 hr? (Round your answers to four...
Thursday, July 11, 2013 at 7:22pm by Shan

physics
There is another way to do this which is a little shorter. Note that the difference between 90 km/hr and 75 km/hr is 15 km/hr. So we ask ourselves how long it takes to cover that additional 0.1 km at the rate of 15 km/hr. That is t=d/r = 0.100/15 = 0.00667 hr. Voila!
Saturday, June 20, 2009 at 1:02pm by DrBob222

9th grade
They are 12 min apart (1/5 hr). relative velocity=25mi/hr time: 1/5 hr at start distance apart=100*1/5=20miles at start timeto catchup= 20miles/25mi/hr= 4/5 hr
Wednesday, March 10, 2010 at 9:56am by bobpursley

Physics
54 km/95 = .5684 hr 54 km/118 = .4576 hr difference = .11 hr .11 hr * 60 min/hr = 6.647 min which is 6 minutes and 39 seconds
Saturday, February 8, 2014 at 11:35am by Damon

physics
The speed of a car moving in a straight line increases every second. It goes from 30 km/hr (about 19 mi/hr) to 35 km/hr (about 22 mi/hr) in the first second. The next second, it goes from 35 km/hr to 40 km/hr (about 24.8 mi/hr). What is its acceleration?
Monday, January 21, 2013 at 6:13pm by Anonymous

physics
The distance to travel is 144m The difference in speed is 16km/hr 144m / 16km/hr * 1km/1000m = 9/1000 hr * 3600s/hr = 32.4s
Saturday, August 31, 2013 at 7:37pm by Steve

MATHEMATICS_motion
72/s = 72/(s+6) + 1/6 s^2 + 6s - 2592 = 0 (s+54)(s-48) = 0 speed = 48km/hr time at 48km/hr: 1.5 hr = 90 min time at 54km/hr: 4/3 hr = 80 min
Tuesday, February 7, 2012 at 8:36pm by Steve

math
Joe 12 b/8 hr = 1.5 b/hr Bob 6 b/12 hr = .5 b/hr together 2 b/hr 2 b/hr * x hours = 12 b x = 6 hours
Thursday, January 26, 2012 at 12:49pm by Damon

Math
Jack --> 1/3 yard/hr Marilyn --> 1/5 yard/hr together 1/3+1/5 = 5/15+3/15 = 8/15 yard/hr so 15/8 hr/yard 15/8 hr/yard * 60 min/hr = 112.5 min = 1 hr 52 1/2 minutes
Thursday, August 12, 2010 at 6:58pm by Damon

Pre Calculus
CORRECTION: Revs = 4 + 45/360 = 4 1/8 = 4.125. V=4.125rev/5min * 60min/hr = 49.5rev/hr V=49.5rev/hr*785.4ft/rev*(1/5280)mi/ft = 7.36mi/hr.
Monday, March 7, 2011 at 12:11pm by Henry

Intergated chemistry/physics
99km/hr / 4sec * 3600sec/hr = 89100 km/hr^2
Wednesday, October 3, 2012 at 11:01am by Steve

math
Let V = tank volume Fill rate = 1/4 V per hr Drain rate = 1/2 V per hr Net loss rate = 1/2 - 1/4 = 1/4 V/hr Drain time = (V/2)/(1/4 V/hr) = 2 hr
Wednesday, September 24, 2008 at 8:23pm by drwls

Physics
d1 = 35 mi/hr * 0.5 hr = 17.5 mi, d2 = 60 mi/hr * 2 hr = 120 mi, d3 = 25 mi/hr * 1/6 hr = 4.17 mi. d = 17.5 + 120 + 4.17 = 141.67 miles, t = 0.5 + 2.0 + 1/6 = 2.67 hrs, Vavg = d / t = 141.67/2.67 = 53.13 mi/hr. 8
Sunday, September 12, 2010 at 9:12pm by Henry

physics
Vb=25km/hr @ 90 deg. = Velocity of boat Vw = 10km/hr @ 330 deg. = Velocity of water. X = hor. = 10cos330 = 8.66km/hr. Y = ver. = 25 + 10sin330 = 20km/hr. tanA = Y / X = 20 / 8.66 = 2.3094. A = 66.6 deg. R=X / cosA = 8.66 / cos66.6=21.8km/hr @ 66.6 deg.=21.8km/hr @ 66.6 deg ...
Sunday, September 4, 2011 at 6:59am by Henry

physical science
Brad rides his bike 20 km. He covers the distance in 45 minutes (0.75 hours). What is his speed in kilometers per hour? A.44 km/hr B.15 km/hr C.9.0 km/hr D.27 km/hr
Sunday, December 18, 2011 at 4:32pm by kelsey

Physics
265km / 60km/hr = 4.42 hr = 4 hr 25 min
Friday, August 24, 2012 at 12:53pm by Steve

11th grade physics
Carl puts the pedal to the metal and increases her speed as follows: 0 mi/hr at 0 seconds; 10 mi/hr at 1 second; 20 mi/hr at 2 seconds; 30 mi/hr at 3 seconds; and 40 mi/hr at 4 seconds. What is the acceleration of Car;'s car?
Monday, November 29, 2010 at 9:30pm by jess

physics
Why are you using 1.1083 hr for total time? You already computed 19.483 hr, which should have been 1.9483 hr.
Tuesday, September 13, 2011 at 6:28am by drwls

8th Grade Science
a= (31km/hr - 29km/hr) / 5sec a= 0.4 km/hr/s That's how I got one of the answers....I am confused at what you are trying to show me.
Tuesday, January 10, 2012 at 8:51pm by Anya

Physics
it was 1 of the options from the text book. a- 1.21 mi/hr b- 55 mi/hr c- 65 mi/hr d- 72.6 mi/hr
Wednesday, April 8, 2009 at 1:09pm by Timetraveler

Algebra II
You can solve it algebraically or you can set up a chart: First train: 1 hr: 75 mi 2 hr: 150 mi 3 hr: 225 mi -- Continue this chart Second train: 1 hr: 100 mi 2 hr: 200 mi 3 hr: 300 mi -- Continue this chart. Compare the charts to see when they've both traveled the same ...
Monday, October 29, 2007 at 5:02pm by Ms. Sue

Algebra I
pump A, 1/3 tank /hr pump B, 1/2 tank/hr in first hour pump A fills 1/3 tank so together they fill 2/3 tank x hours (1/3 tank/hr + 1/2 tank/hr) = 2/3 tank x (5/6) = 2/3 = 4/6 5 x = 4 x = 4/5 hr = (4/5)60 = 48 minutes
Wednesday, June 30, 2010 at 5:59pm by Damon

8th Grade Science
A runner whose initial speed is 29 km/hr increases her speed to 31 km/hr in order to win a race. If the runner takes 0.5 seconds to complete this increase in speed, what is her acceleration? I think it's either 1440 km/hr/hr or 0.4 km/hr/sec. Are you supposed to convert the ...
Tuesday, January 10, 2012 at 8:51pm by Anya

math
s*(1/2) = (s-10)(1/2 + 1/6) s = 40 check: 40mi/hr * 1/2 hr = 20 mi 30mi/hr * 2/3 hr = 20 mi
Saturday, January 12, 2013 at 7:12pm by Steve

physics URGENT! PLEASE
Figure the resultant velocity of a plane that is traveling at 300 km/hr @ 190 degrees when he encounters the wind below a) 30 km/hr tailwind b) 40 km/hr headwind c) 50 km/hr wind blowing south
Monday, October 15, 2012 at 5:23pm by Anna

Math Help
since the bus catches up 175 km in 5 hrs, that's a speed difference of 35 km/hr. So, the bus went 10+35 = 45 km/hr Your solution is in error. It should be 225km/5 hr = 45 km/hr (Also, the units are wrong in your 1st line: 10km/hr * 5 hr = 50 km, not 50km/hr) another solution ...
Thursday, March 6, 2014 at 2:17pm by Steve

physics
The first question is when do they meet? distance apart 8mi relative velocity is 9mi/hr time= distance/velocity= 8/9 hr how far did B go? distance= 5mi/hr*8/9 hr= 40/9 mi so they met (40/9-4) miles West of the flagpole.
Wednesday, September 1, 2010 at 8:45pm by bobpursley

physics- what did i do wrong
If the bus is 100 meters ahead of the car and the bus is travling at 65 km/hr and the car at 78km/hr, how long will it take the car to catch the bus? I used the following formula, but was informed my answer was wrong. 100m + (t) 65km/hr = 0 + (t)78km/hr and solved for (t). t...
Wednesday, August 29, 2007 at 4:00pm by jeff

Intergrated Algerbra
hard to say. All we know is that their combined speed is 60 ft/hr They could both have traveled 30 ft/hr or, the snail could have traveled 10 ft/hr and the caterpillar 50 ft/hr or lots of other combinations.
Thursday, November 29, 2012 at 4:29pm by Steve

Physics
a= deltav/time= 60mi/hr/3 sec Vf=at 4mi/hr= 20mi/hr*sec * t t= 4/20 of a second.
Sunday, October 11, 2009 at 6:23pm by bobpursley

algebra
S --> 1/8 program per hr M --> 1/12 prog / hr together 1/8 + 1/12 = 3/24+2/24 = 5/24 prog/hr so 24/5 = 4 4/5 hr/prog 4/5 hr * 60 min/hr = 48 minutes so 4 hours and 48 minutes
Wednesday, December 1, 2010 at 3:45pm by Damon

Physics
Vo=0km/h V1=89 km/h t0=0 t1=6.1 89-0/6.1-0=14.5 km/hr (Round to 2 sig figs=15 km/hr) You then have to convert km/hr to m/s^2. 15km/hr * 1000m/3600s= 4.1m/s^2 3600s = 1hr *hope that helps
Thursday, October 21, 2010 at 7:34pm by Samantha

science
We will assume that the question is asking for the answer in m s^-2. I would also draw a picture and define the positive direction as the direction of travel. Note that the symbol for time is s not sec. First convert the velocity km hr^-1 to m s^-1 72 km h^-1 is 72 x 1000 m km...
Monday, October 3, 2011 at 7:23am by Dr Russ

Chemistry- that is correct.
Yes. 34m/s = 34m/s * 1000mm/m * 60s/hr = 2040000mm/hr ≈ 2.010^6mm/hr
Sunday, September 22, 2013 at 6:23pm by Graham

physics
12 min is 12/60 or 1/5 hr distance=35km/hr * 1/5 hr= 7 km It is right.
Monday, June 29, 2009 at 3:47pm by bobpursley

Physics
ok,ok,ok....lad listen up lets see how ya did here... THESE ARE THE CORRECT ANSWERS... 1a) 85 km/hr = 23.61 m/s (HINT: from km/hr to m/s just divide by 3.6) 1b) d = vt = (23.61)(8) = 188.88 m 1c) t = d/v = (2000)/(23.61) = 84.7 s 1d) v = d/t = (140)/(1.83) = 76.5 km/hr (HINT: ...
Wednesday, June 5, 2013 at 9:20pm by herp_derp

physics
At 7.35 cents per kiloway hr, A. what does it cost to operate a 10.0 hp motor for 8.00 hr? B. What does it cost to leave a 75W light burning 24 hr a day?
Tuesday, October 18, 2011 at 9:48am by Micah

maths
to rise by 2.4m in 18 hours, the volume must increase by 120*.75*2.4 = 216 m^3/hr the square pipe has cross-section area of .2^2 = .04 m^2 216 m^3/hr / .04m^2 = 5400 m/hr
Wednesday, December 19, 2012 at 5:41am by Steve

physics
To get the average speed during the entire trip, divide the total distance by the total time. part 1: 14mi/50mph = 0.28 hr part 2: 28.3mi/48mph = 0.59 hr part 3: 37.4mi/38.3mph = 0.98 hr total: 79.7mi/1.85hr = 43.1mi/hr
Tuesday, September 27, 2011 at 5:47pm by Steve

math
289 min = 4 hr and 49 min 213 min = 3 hr and 33 min 345 min = 5 hr and 45 min 197 min = 3 hr and 17 min I have to change these minutes on the left to hours and minutes. could you check if I have them correctly. Thank you for your help
Monday, April 26, 2010 at 7:41pm by st

math115
I get the same answer as melody on the first one, but please do check my arithmetic: 1/4 hr = 60 / 4 = 15 min 2/3 hr = 120 / 3 = 40 min 4/5 hr = 240 / 5 = 48 min 15 + 40 + 48 = 103 min = 1 hr 43 min
Tuesday, October 20, 2009 at 5:29pm by jim

The Heart
What is the relationship between fitness level and recovery HR after sub-maximal exercise? I was thinking the more fit you are, the faster your HR will drop back to what it is when you're resting. If you're unfit, it'll take longer for that HR to go down to resting.
Sunday, April 11, 2010 at 11:06pm by Lena

math
Just plod along step by step. a) halfway is 60 miles in 1.2 hr = 60/1.2 = 50 m/hr b) 60 miles at 40 miles per hr = 1.5 hr 1.5 c) 55*2 = 110 120 - 110 = 10
Saturday, April 11, 2009 at 2:54pm by Damon

Math
Stephanie cleans at the rate of 1 pools/hr. Mark cleans at the rate of 1/1.5, or 2/3 pools/hr. Their combined rate is 5/3 pools/hr If r is the rate, t is time, and p is the number of pools, then r = p/t (5/3pools/hr) = (1 pool)/t t = 3/5hr t = 60*3/5 = 36min
Monday, July 13, 2009 at 3:41pm by Marth

Physics
Jason drives due west with a speed of 35.0 mi/hr for 30 mins, then continues in the same direction with a speed of 60.0 mi/hr for 2.00 hr then drives farther west at 25.0 mi/hr for 10.0 mins. What is his average velocity?
Sunday, September 12, 2010 at 9:12pm by Dakota S

physics
d1 = 10km. d2 = 40km/hr * (6/60)hr = 4km. Vavg = (di + d2) / (t1 + t2), Vavg=(10 + 4) / (0.5 + 0.1)=23.3km/hr.
Sunday, July 24, 2011 at 2:50am by Henry

physics
d1 = 10km. d2 = 40km/hr * (6/60)hr = 4km. Vavg = (di + d2) / (t1 + t2), Vavg=(10 + 4) / (0.5 + 0.1)=23.3km/hr.
Sunday, July 24, 2011 at 2:50am by Henry

Algebra II
add up the times time = distance/speed If his downhill speed is s, 8/s + 8/(s-3) = 4 s = 6 check: 8 miles @ 3mph = 8/3 hr 8 miles @ 6mph = 4/3 hr total: 4 hr
Thursday, November 15, 2012 at 2:03pm by Steve

Maths / Physics
Relative to driver? Falling at 25km/h, horizontal at 82km/hr Velocity= 25km/hr DOWN+82KM/hr TowardBack so add these as vectors.
Sunday, January 2, 2011 at 11:37am by bobpursley

oops--Chemistry- is this correct?
I don't agree with either. Both left out a factor of 60 to convert min to hr. 2.04E6 is really mm/min. To convert to mm/hr use 2.04E6mm/min*60 min/hr = 1.2E8 mm/hr
Sunday, September 22, 2013 at 6:23pm by DrBob222

Anatomy (The Heart)
What is the relationship between fitness level and recovery HR after sub-maximal exercise? I was thinking the more fit you are, the faster your HR will drop back to what it is when you're resting. If you're unfit, it'll take longer for that HR to go down to resting.
Sunday, April 11, 2010 at 5:43pm by Lena

physics
distance one way = 25mi/hr * 1/3 hr = 25/3 mi total distance = 50/3 mi total time = 1/3 +1 + (25/3)/15 = 17/9 hr avg speed = 50/3 mi / 17/9 hr = 150/17 = 8.82 mi/hr avg velocity = 0, since he traveled no net distance.
Wednesday, November 14, 2012 at 4:38pm by Steve

Math
The speed limit on a highway is 65 mi/hr. What is this speed in km/hr? Is the correct answer 104 km/hr?
Saturday, February 25, 2012 at 10:39am by Mandi

Chemistry
6 mi/hr x ?hr = 704 calories. Solve for ?hr. There are 1000 cal in a kcal. There are 4.184 J in a cal There are 1000 J in a kJ.
Thursday, October 25, 2012 at 8:46pm by DrBob222

8th Grade Science
a = change in velocity/change in time change in velocity = 31000 m/hr/3600 s/hr - 29000m/hr/3600 s/hr = .56 m/s so .56 m/s / .5 s = 1.11 m/s^2
Tuesday, January 10, 2012 at 8:51pm by Damon

Unit Conversion. Help Please.
the idea is to convert both distance and time. 55mi/hr change distance first 55mi/hr*1760yds/miHr=55*1760yds/hr then time 55*1760yds/hr*1hr/60min= 1760*55/60 yds/min
Friday, January 11, 2013 at 7:10pm by bobpursley

math
useful conversion: 1 km = 1000 m 1 hr = 60 min = 60*60 s *note: you can rewrite 846 km/hr into: (846 km)*(1/hr) thus, using dimensional analysis to cancel units, (846 km)*(1000 m / 1 km) = 846*1000 m (1/hr)*(1 hr / 60*60 s) = 1 / 60*60 s now multiply both: 846*1000 * 1/(60*60...
Friday, October 29, 2010 at 3:55am by jai

physics
I am interpreting your first two sentences as meaning: "A man running horizontally along a road, with velocity 8 km/hr, finds the rain falling in a vertically downward direction." That statement implies that the rain has a horizontal component of 8 km/hr in the same direction ...
Thursday, July 28, 2011 at 2:32pm by drwls

math
(1/2) hr/ (1/8) mile = 4 hr/mile 2.5 miles * 4 hr/mile = 10 hr
Sunday, January 29, 2012 at 3:59pm by Damon

math
Memorize this: 60mi/hr=88ft/min Memorize it. It saves a lot of time forinstance, 30mi/hr then is 44ft/min 10mi/hr=88/6 ft/min
Sunday, November 28, 2010 at 3:47pm by bobpursley

Pre Calculus
C=3.14 * 250ft 785.4ft.=Circumference. Revs = 4 + (360-45) / 360, Revs = 4 + 315/360 = 4 7/8 = 4.875. V=4.875rev/5min * 60min/hr=58.5rev/hr, V=58.5rev/hr*785.4ft/rev*(1/5280)mi/ft = 8.7mi/hr.
Monday, March 7, 2011 at 12:11pm by Henry

physics
Jason drives due west with a speed of 55.0km/hr for 30.0 min, then continues in the same direction with a speed of 95.0km/hr for 2.00 hr, then drives farther west at 40.0km/hr for 10.0 min. What is the magnitude of Jason's average velocity
Tuesday, September 27, 2011 at 11:40pm by Janie

MATH
I assume you mean R miles per hour d = T*R keep track of the units d (mi) = T(hr) * R (mi/hr) The "hr" units cancel, leaving only "mi"
Thursday, May 24, 2012 at 5:47pm by Steve

math
Achewy: X hrs. @ $9.00/hr. Coughy: (x+4) hrs. @ $6.50/hr Pokey:(x+4)/2 hrs. @ $5.00 hr. 9x + 6.5(x+4) + 5(x+4)/2 = 252. Multiply both sides by 2 and solve for x.
Wednesday, June 6, 2012 at 12:23am by Henry

Math
The time t required to drive afixed distance varies inversely as the speed r. It takes 5 hr at a speed of 80 km/h to drive a fixed distance. How long will it take t odrive the same distance at a speed of 70 km/hr? Please help! In an inverse dependence situation, the product of...
Wednesday, October 25, 2006 at 8:32am by Dee Williams

IPC
Again, we start with the question: What would the final speed of a car be after 5.0 seconds with a starting speed of 50 mi/hr? What is needed to solve this equation: Acceleration of the car. Yes that is all that is necessary. To find the acceleration, this is where the 0-60 mi...
Tuesday, September 11, 2012 at 9:48pm by Jason

math
1 hr * 60 min/hr * 240 people/turnstile/5min * 8 turnstile = 23040 people/hr
Saturday, November 24, 2012 at 9:32am by Steve

Algebra
15. Rate upstream=30/4=7.5m/hr Rate downstream=30/2.5=12m/hr Rate in stillwater=(7.5+12)/2=9.75m/hr
Saturday, June 12, 2010 at 6:34pm by Henry

physics
5sec = 5/3600 hours change in velicity is 90 km/h in 5/3600 hrs so the acceleration is 90km/h/(5/3600 hr) = 90*3600/5 km/hr^2 = 64800 km/hr^2 Not the units you wanted? Well, I'll let you change from km/hr^2 to m/s^2
Saturday, November 19, 2011 at 12:50pm by Anonymous

Math
No, you have an upside-down fraction ft/sec x sec/min = ft/min ft/min x min/hr = ft/hr ft/hr x m/ft = m/hr <<<---- m/hr x km/m = km/hr
Monday, October 10, 2011 at 5:01pm by Steve

maths
BLUE travels for x hours, starting at 2:00 95 minutes = 19/12 hrs, so RED travels for (x-31/12) hrs, starting at 4:35 35x + 50(x-31/12) = 500 x ~= 7.4 hrs so they meet at 2:00 + 7.4 = 9:24 pm check: 35km/hr for 7.4 hr = 259km 50km/hr for 4.817 hr = 241km
Friday, March 22, 2013 at 3:50pm by Steve

algebra
Let V be his speed going up so V+18 will be his speed going down, in miles/hr. The time required is 14/60 hr = 0.2333 hr = 2/V + 2/(V+18) Solve for V
Sunday, June 29, 2008 at 1:43pm by drwls

Calculus - Related Rates
12mm^2/hr = r2PI dr/dt So 12/2PIr mm^2/hr = dr/dt which is the same as dr/dt = 6/PIr mm^2/hr Why'd you originally say dr/dt= 12/(2r) mm/hr
Sunday, November 29, 2009 at 5:42pm by Joel

Calculus
I assume "most economical" means lowest cost per mile. The driver's wages: $/mi = $/hr * hr/mi = $/hr / (mi/hr) The truck: $/mi = $/gal * gal/mi = ($/gal) / (mi/gal) If speed is x, and y is cost/hr, including the driver's wages y = 8/x + 1 * 1/(377/x) y = 8/x + x/377 For ...
Friday, November 4, 2011 at 12:20pm by Steve

College Physics
depends on whether he cares how far downstream the boat drifts. Minimum time is achieved by heading perpendicular to the bank. In that case, he has to go 1.6km at a speed of 15km/hr. min time is thus 1.6km / 15 km/hr = .10666 hr = 6.4min
Wednesday, September 12, 2012 at 3:58pm by Steve

math
first, convert everything to the same units. I expect km/hr would be good here. Japan: 320 km/hr France: 89.44 m/min = 322 km/hr So, any speed between those two would be second fastest.
Thursday, January 2, 2014 at 6:34pm by Steve

Chemistry
1 Megameter = 10^6 meters 1 meter = 100 cm I'll convert megameters to meters for you. (41.2 megameters/hr)(10^6 meters/1 megameter)(100 cm/ 1 meter)=___m/hr notice how all the units cancel to m/hr now that you have m/hr, please convert hr to sec, knowing that 1 hour = 60 min, ...
Wednesday, September 15, 2010 at 7:16pm by TutorCat

math
ah: { 1/Tt } = 1/Tf + 1/Ts because A --> 1/3 rooms per hr B --> 1/4 rooms/hr (A+B) --> 1/3 + 1/4 rooms/hr = 7/12 rooms per hr which is 12/7 hours/room
Friday, May 1, 2009 at 2:05am by Damon

physics
34km/hr * 1000m/km * hr/3600 = 9.444 m/sec v = v0 + at = 9.444 + 3.9*6.8 = 35.964 m/sec = 129 km/hr
Thursday, September 22, 2011 at 5:23pm by Steve

Math word problem
I am having problems with this part: add the equations... 33+63)km/time=64km/hr then time= 96/64 hr (I know this is 1.5) Now solve for speed of wind in the first equation.. (is it 33km/1.5 =22) 33km/time=32km/hr-speedwind.
Sunday, October 12, 2008 at 1:42pm by Erica

math
4in/hr = 1/15 in/min = 1/3 ft/hr Surely the last part you can do. 8pm to 12pm is 4 hours. At 4 in/hr, that means ? inches. PS 12pm is bogus. 12:00 is either noon or midnight. PM means post-meridiem, which is after noon
Sunday, November 24, 2013 at 2:39am by Steve

math
I solve these by the following: 1 house/4 hours = 0.25 house/hr. 1 house/6 hours = 0.157 house/hr. If they paint together they will have those combined or 0.25 house/hr + 0.167 house/hr = 0.417 house/hour. or 1/0.417 hours/house = 2.4 hours.
Sunday, April 4, 2010 at 11:31pm by DrBob222

physics
Let's convert km/hr to m/s 36km/hr * 1000m/km * hr/3600s = 10m/s how convenient. at 5.0i the velocities just add: 10i + 5i = 15im/s same for -5i: 10i-5i=5im/s when running at 5.0j, we have 10i+5j, so the speed is sqrt(100+25) = 11.2m/s direction θ has tanθ = 5/10, so...
Wednesday, January 11, 2012 at 11:13pm by Steve

math
1. kristi jogged for 3/5 of an hr,swam 1/2 of an hr, rode her bike 3/4 of an hr how long did she exercise?=1 7/20 2.the intersest rate on an equity line of credit was 7 7/8% last month this month the interset rate is 10 3/2% how many percentage points has the interset rate ...
Saturday, September 19, 2009 at 4:39pm by p

physics
1.A train passes an electric post in 8sec and a bridge of length 1km in 108sec .Find the speed of the engine . 2.A runner travels at the rate o f25km/hr for 4min ;then at 50km/hr for 8minn and finally at 20km/hr for 2min .Find a) the total distance covered in km and b)average ...
Saturday, May 19, 2012 at 1:38am by srikar

Physics
I am having a problem answering a physics question: A plane is heading due south and climbing at the rate of 60 km/hr. If its airspeed is 540 km/hr and there is a wind blowing 110 km/hr to the northwest, what is the ground speed of the plane?
Sunday, March 17, 2013 at 10:26pm by Patrick

Algebra
John --- 1/6 lwn/hr Jane --- 1/3 lwn/hr 1/6 + 2/6 = 3/6 = 1/2 lwn/hr so 2 hours
Saturday, December 17, 2011 at 6:08pm by Damon

algebra
since the speed difference is 2 km/hr, (1/4 km) / (2 km/hr) = 1/8 hr
Saturday, April 19, 2014 at 4:06am by Steve

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