a) correct, where d is in feet and t is in seconds, careful with brackets
d = (4√106)t
b) Your time is in hours, so 3 hours and 15 min = 3.25 hours
= 3.25*3600 s
= 11700 seconds
d = 4√(106) * 11700) = appr 481,835.49 ft
= 481,835.49/5280 miles
= appr 91.3 miles
c) when is 4√106 t = 1 mile = 5280 ft
4√106 t = 5280
√106 t = 1320
t = 1320/√106 = 128.2 seconds
= appr 2 minutes.
this makes sense, since 20 ft/s = (20/5280) / (1/3600) mph = appr 13.6 mph
and 36 ft/s = 24.5 mph (rounded off to 1 decimal)
so after 1 hours D = √(13.6^2 + 24.5^2) = 28 mile
so in 3.25 hours, D = 3.25(828) = 91
As a matter of fact it might have been easier to change it all to mph at the
beginning, but hey, what difference does it make with calculators.
Suppose two cars depart from a four-way intersection at the same time, one heading north and the other heading west. The car heading north travels at the steady speed of 20 ft/sec and the car heading west travels at the steady speed of 36 ft/sec.
(a) Find an expression for the distance between the two cars after t seconds. (Round your coefficients to one decimal place as needed.) ft
(b) Find the distance in miles between the two cars after 3 hours 15 minutes. (Round your answer to one decimal place.) in mi
(c) When are the two cars 1 mile apart? (Round your answer to one decimal place.) in sec
this is what I have so far
(a) d=√((20t)^2+(36t)^2)=4√106t
(b) t=3*3600+15*60=11,700 in (a) / 5280
(c) solve for t when d = 5280
I get lost from here
6 answers
What would you get for part (a) iam still lost on that one
a) you had d = 4√106 t, which I said is correct
so I don't understand why you are lost.
If you wanted the actual value of 4√106 that would be appr 41.2
but we should not round off too soon. With todays calculators there is no
need to round off until you reach the final answer.
I have a 25-year old SHARP, with 7 different memory locations.
(very sophisticated for those times)
I use these to store my intermediate answers and only after the last
calculation do I round off.
so I don't understand why you are lost.
If you wanted the actual value of 4√106 that would be appr 41.2
but we should not round off too soon. With todays calculators there is no
need to round off until you reach the final answer.
I have a 25-year old SHARP, with 7 different memory locations.
(very sophisticated for those times)
I use these to store my intermediate answers and only after the last
calculation do I round off.
Well the answers needs to be in ft and it says 4√106 and 41.2 is wrong so ?
file:///C:/Users/grant/Downloads/qrcode_www.webassign.net.png
sorry wrong website
1 answer