HELP Assignment due in an hours

[kara]

HELP ! Assignment due in an hours

A gold ball is hit from ground @ 25* to the horizontal. When it lands, it has a velocity of 20 m/s @ 30* below horizontal.
A) find initial speed
B) time that ball is in air
C) height of landing pt. relative to start pt, which may be positive or negative

 

[Hootenanny]

https://www.physicsforums.com/showpost.php?p=905663&postcount=2

 

[kara]

i've got another one too..
A motorcycle is stationary at traffic light. At t=0s, light turns green and it accelerates at 3m/s2 when light turns gree, a car is 40 m behind the motorcycle and traveling at 15m/s. At that instant, car slows down at a constant rate so it is never closer than 5 m to motorcyle.
A) time when car is closest to motorcycle
B) instant rate of car stopping
C) distance traveled by motorcycle from light turning green to tim in A)

 

[Hootenanny]

RE: See above post.

 

[kara]

1/2at2 - 1/2(1.5)t2 + 15t -35.0 = 0 what do i do from there

 

[kara]

a = (3t-15.0)/t is what i got for a
Now i need to sub that into above to solve for t

 

[BunDa4Th]

i suggest setting two equation one for motorcycle and one for the car then combine the two equation 1 = equation 2 and solve for T i believe.