SOLUTION: Sarah drives east for 45mins at 80km/h, then makes a 45 degree turn into a dirt road which she drives for 30mins at 40km/h. a) Determine an exact expression for her distance tra

Algebra ->  Trigonometry-basics -> SOLUTION: Sarah drives east for 45mins at 80km/h, then makes a 45 degree turn into a dirt road which she drives for 30mins at 40km/h. a) Determine an exact expression for her distance tra      Log On


   



Question 1011945: Sarah drives east for 45mins at 80km/h, then makes a 45 degree turn into a dirt road which she drives for 30mins at 40km/h.
a) Determine an exact expression for her distance travelled.
b) Use as a calculator to determine the distance to the nearest kilometre.
Please help I'm lost :(

Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
.
Distance=Rate x Time
.
D%5BE%5D=Distance east; R%5BE%5D=Rate traveled east=85 km/h;
T%5BE%5D=Time traveled east=45 min= 0.75 hour
.
D%5BA%5D=Distance at angle; R%5BA%5D=Rate traveled at angle=40 km/h;
T%5BA%5D=Time traveled at angle=30 min=0.5 hour
.
D%5BT%5D=Total distance traveled
.
D%5BT%5D=D%5BE%5D%2BD%5BA%5D
D%5BT%5D=%28R%5BE%5D%29%28T%5BE%5D%29%2B%28R%5BA%5D%29%28T%5BA%5D%29
D%5BT%5D=%2885km%2Fh%29%280.75h%29%2B%2840km%2Fh%29%280.6h%29
D%5BT%5D=63.75km%2B24km
D%5BT%5D=87.75km
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