Plunk and Ms. Q run a 100-meter race. Plunk runs at 8 meters per second, and Ms. Q runs at 5 meters per second. Because Ms. Q runs slower, she is given a 3-second head start. Plunk wins the race. How much time, in seconds, is it between the time Plunk passes Ms. Q and the time that Plunk finishes the race?

Guest Mar 5, 2021

#1**+1 **

3 second head start = 3x 5 = 15 meters

difference in speed 8- 5 = 3 m/s 15 / 3 = 5 seconds when P catches Q (this 8 seconds after Q starts)

in 5 seconds P runs 5 * 8 = 40 meters this is when they are at the same point

60 meters left in the race will take P 60 m / 8 m/s =** 7.5 seconds** to finish

ElectricPavlov Mar 5, 2021