Saturday

April 18, 2015

April 18, 2015

Posted by **dave** on Sunday, November 29, 2009 at 9:52pm.

i am solving for tf and i have it worked all the way down to:

-100m(tf)-100m(tf) / -10m/s^2(tf)^2

or

-200m(tf) / -10m/s^2(tf)^2

is the answer 20 seconds? algebra is not my strong suit =(

- Need problem statement -
**Damon**, Sunday, November 29, 2009 at 9:58pmWhat is the problem here. Is it something fired at some speed at some angle?

- college physics -
**dave**, Sunday, November 29, 2009 at 10:03pmyes.. it's the "brothers of mercy" problem.

a plane is flying at 40 m/s, descending at an angle of 37 degrees to the horizontal. it is 100 m in the air and it is trying to drop a package to a man at R distance. what is R?

to find R, i needed to solve for time. that's where the quadratic came from

- college physics -
**Damon**, Sunday, November 29, 2009 at 10:55pminitial speed down = 40 sin 37

= 24.1 m/s

falls 100 meters, get speed down

v = 24.1 + 9.8 t

distance down

100 = 24.1 T + 4.9 T^2

4.9 T^2 + 24.1 T - 100 = 0

T = 2.68 s

now horizontal speed constant for 2.68 seconds

d = (40cos37)2.68

= 85.6 meters

**Answer this Question**

**Related Questions**

physics - Stickman is driving a dragster. He does the quarter mile in 4 seconds ...

physics - Stickman is driving a dragster. He does the quarter mile in 4 seconds...

physic/math - What happens when ocean waves with (a) wavelength=10m and (b) ...

Science - A ball is tossed at 10m/s off the top of a 100m tall building. Find ...

chemistry - Four solution are prepared and mixed together: Start with 100.0ml of...

Physics - For a question in physics... I was told to draw a graph of vertical ...

Physics - A projectile is shot horizontally at 30m/s from the roof of a building...

Physics - A projectile is shot horizontally at 30m/s from the roof of a building...

Physics - A projectile is shot horizontally at 30m/s from the roof of a building...

Chem - The apparent equilibrium constant for the reaction A + B <==> 2C is...