Jack and Jill's Race: Solving a Physics Problem

[deaninator]

Homework Statement

Jack and Jill ran down the hill, Both started from rest and accelerated steadily. Jack accelerated at .25 m/s/s and Kill at .30 m/s/s. After running for 20 s, Jill fell down.
A) How far did Jill get before she fell? 60m
B) How far had Jack traveled when Jill fell? 50m
C)How fast was Jack running when Jill fell? 5 m/s
D) How long (to the nearest second) was it after Jill fell that Jack ran into her and broke his crown? ?

Homework Equations

V=Vo + at
X=1/2(Vo +V)T
X=VoT + 1/2at2
V2=Vo2 + 2ax

(If a 2 is after a letter then it means squared)
X=displacement
A=Acceleration
T=Tome
Vo=Initial Velocity
V=Velocity

The Attempt at a Solution

I just don't know how to figure D...please help.

 

[dickface]

you need an x to get it done imho. presume the nearest second is x, and calculate the distances they have run treating x as a known value. the distances are supposed to be equal ( when Jill fell that Jack ran into her and broke his crown), then its only math work to do.

 

[deaninator]

you need an x to get it done imho. presume the nearest second is x, and calculate the distances they have run treating x as a known value. the distances are supposed to be equal ( when Jill fell that Jack ran into her and broke his crown), then its only math work to do.

Thanks.
So ok Distance is suppose to be the same, that makes sense. But they both ran different distances though...

 

[dickface]

Thanks.
So ok Distance is suppose to be the same, that makes sense. But they both ran different distances though...

sorry tbh, i misunderstood it. x is only needed when they start the run with a given distance between them, and the one starting behind runs faster so he will overtake the other at some point of time. this point of time is often presumed as x.

the question you offered isn't that complex tbh. jill stopped running as soon as he fell, so you only need to calculate the distance jill had run before she fell, and calculate how much time jack would need to arrive at the point where jill fell down.

 

[deaninator]

sorry tbh, i misunderstood it. x is only needed when they start the run with a given distance between them, and the one starting behind runs faster so he will overtake the other at some point of time. this point of time is often presumed as x.

the question you offered isn't that complex tbh. jill stopped running as soon as he fell, so you only need to calculate the distance jill had run before she fell, and calculate how much time jack would need to arrive at the point where jill fell down.

I got it, thanks Dickface.