Saturday

October 25, 2014

October 25, 2014

Posted by **Jack** on Tuesday, July 17, 2012 at 10:55pm.

y(f) = y(i) + v(i)t+1/2at^2

y(f) and y(i) = final and initial position, v(i) = initial velocity, a = acceleration, and t = time, respectively.

- Biomechanics -
**Steve**, Wednesday, July 18, 2012 at 11:00amvelocity is 50-9.8t.

v=0 at top of trajectory, at t=50/9.8=5.10 sec.

y = yi + 50t - 4.9t^2, so at t=5.10,

20 = yi + 50(5.10) - 4.9(5.10)^2

yi = -107.55

eh? thrown from below ground?

Yet it makes sense, since it was thrown upward with a velocity of 50 m.s, yet only made it 20m high. No mention was made of a horrific air resistance.

Anyway, assuming the above,

y = -107.55 + 50t - 4.9t^2

solve for t when y=10:

t = 3.67 or 6.53

If I botched it, make the fix.

**Answer this Question**

**Related Questions**

Math - The height(h) of an object that has been dropped or thrown in the air is...

Math - The height(H) of an object that has been dropped or thrown in the air is ...

math - A ball is thrown into the air with an upward velocity of 20 ft/s. Its ...

Math Help (URGENT X10) - This is really urgent so please please please help. The...

kinetics - a ball of mass 200 g is thrown vertically upwards with a velocity of ...

kinetics - a ball of mass 200 g is thrown vertically upwards with a velocity of ...

physics - A ball is thrown straight downward from the surface of the moon. Is ...

calculus - If a ball is thrown vertically upward from the roof of 64 foot ...

Physics - A 0.150kg baseball is thrown upwards with an initial speed of 20.0 m/s...

Calculus - If a ball is thrown vertically upward from the roof of 32 foot ...