- #1
lpcampbe
- 15
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A bicyclist rides 6.2 km due east, while the resistive force from the air has a magnitude of 2.7 N and points due west. The rider then turns around and rides 5.5 km due west. The resistive force from the air on the return trip has a magnitude of 2.2 N and point due east. Find the work done by the resistive force during the round trip.
W = F*distance
I figured I was given some vectors to work with:
Vector A = 6.2 km E
Vector B = 2.7 N W
Vector C = 5.5 km W
Vector D = 2.2 N E
Vectors A and B directly affect each other, and Vectors C and D affect each other.
Since W = F * distance:
6.2 km * -2.7 N = -16.74 J (negative N because it's pointing due West)
5.5 km * 2.2 N = 12.1 J (positive N because it's pointing East, positive km because distances can't be negative)
-16.74 J + 12.1 J = -4.64 J (not the right answer)
What am I doing wrong?
W = F*distance
I figured I was given some vectors to work with:
Vector A = 6.2 km E
Vector B = 2.7 N W
Vector C = 5.5 km W
Vector D = 2.2 N E
Vectors A and B directly affect each other, and Vectors C and D affect each other.
Since W = F * distance:
6.2 km * -2.7 N = -16.74 J (negative N because it's pointing due West)
5.5 km * 2.2 N = 12.1 J (positive N because it's pointing East, positive km because distances can't be negative)
-16.74 J + 12.1 J = -4.64 J (not the right answer)
What am I doing wrong?