Posted by grace on Sunday, October 24, 2010 at 9:31pm.
Two cars travel westward along a straight highway, one at a constant velocity of 85 km/hr, and the other at a constant velocity of 115 km/hr.
a) Sketch the velocity vs. time graph for both cars and paste your sketch in the space below.
b) Assuming both cars start at the same point, how much sooner does the faster car arrive at a destination 16 km away?
c)How far must the cars travel for the faster car to arrive 15 min before the slower car?
Physics - Henry, Monday, October 25, 2010 at 5:03pm
b. d1 = 85t1 = 16 km,
85t1 = 16,
t1 = 16 / 85 = 0.1882 h = 11.29 min.
d2 = 115t2 = 16 km,
115t2 = 16,
t2 = 16 / 115 = 0.139 h = 8.35 min.
t1 - t2 = 11.29 - 8.35 = 2.94 min.
Car #2 arrives 2.94 min. sooner.
c. 15 min = 1/4 h = 0.25 h.
d1 = d2,
115t = 85(t + 0.25),
115t = 85t + 21.25,
115t - 85t = 21.25,
30t = 21.25,
t = 21.25 / 30 = 0.71 h,
d = 115 * 0.71 = 81.65 km.
Answer This Question
More Related Questions
- Physics - A car moves in a circular path at 15 mph. Which of the following ...
- Physics - Two cars cover the same distance in a straight line. Car A covers the...
- physics - Two cars cover the same distance in a straight line. Car A covers the ...
- Physics - Two cars pass each other traveling at the same speed. One car has a ...
- physics - Assume a canister in a straight tube moves with a constant ...
- Physics Help Please!!!! Graphs Please Please!!! - ------A part is on an assembly...
- phyics - If two cars are traveling along a straight road, one behind the other...
- Physics - A boy is cycling at a constant speed along a straight road to his ...
- physics - A small first aid kit is dropped by a rock climber who is descending ...
- Physics - Two equal mass cars collide head to tail and their bumpers lock. One ...