Physics

Two identical pellet guns are fired simultaneously from the edge of a cliff. These guns impart an initial speed of 36.3 m/s to each pellet. Gun A is fired straight upward, with the pellet going up and then falling back down, eventually hitting the ground beneath the cliff. Gun B is fired straight downward. In the absence of air resistance, how long after pellet B hits the ground does pellet A hit the ground?

1. 👍 0
2. 👎 0
3. 👁 330
1. A: d=Va*t1-4.9t1^2
B: d=-Va*t2-4.9t2^2
set them equal
-Va*t2-4.9t2^2=Va*t1-4.9t1^2
-Va(t1+t2)=4.9(t2^2-t1^2)

-Va(t1+t2)=4.9 (t2-t1)(t2+t1)
-Va=4.9(t2-t1)
or t1-t2=Va/4.9

1. 👍 0
2. 👎 0
2. the time for the pellets to hit the ground is

A: h + 36.3t - 4.9t^2
B: h - 36.3t - 4.9t^2

I expect you will need to know h (the height of the cliff) to solve for the two values of t and take their difference.

A: t = (-36.3 ±√(1317.69+19.6h))/9.8
B: t = (36.3 ±√(1317.69+19.6h))/9.8

The difference is .20√(1317.69+19.6h) - 7.41

1. 👍 0
2. 👎 0
posted by Steve
3. Hmmm. bobpursley is usually right on these matters. I'll have to think on it a bit to see why the initial height makes no difference.

1. 👍 0
2. 👎 0
posted by Steve
4. because when the one that was fired upward gets down to cliff level it is traveling downward at the same initial speed down as the first one was.

1. 👍 0
2. 👎 0
posted by Damon

Similar Questions

1. physics

Two identical pellet guns are fired simultaneously from the edge of a cliff. These guns impart an initial speed of 44.7 m/s to each pellet. Gun A is fired straight upward, with the pellet going up and then falling back down,

asked by sarah on August 6, 2015
2. Physics

Two identical pellet guns are fired simultaneously from the edge of a cliff. These guns impart an initial speed of 27.3 m/s to each pellet. Gun A is fired straight upward, with the pellet going up and then falling back down,

asked by Kaleem on February 7, 2015
3. Physics

Before working this problem, review Conceptual Example 15 . A pellet gun is fired straight downward from the edge of a cliff that is 22.3 m above the ground. The pellet strikes the ground with a speed of 34.9 m/s. How far above

asked by Briana on September 12, 2013
4. physics

A pellet gun is fired straight downward from the edge of a cliff that is 23.1 m above the ground. The pellet strikes the ground with a speed of 38.6 m/s. How far above the cliff edge would the pellet have gone had the gun been

asked by Shawn on September 10, 2013
5. physics

A pellet gun is fired straight downward from the edge of a cliff that is 23.1 m above the ground. The pellet strikes the ground with a speed of 38.6 m/s. How far above the cliff edge would the pellet have gone had the gun been

asked by Shawn on September 10, 2013
6. Math/Science

Three bullets are fired simultaneously by three guns aimed toward the center of a circle where the bullets mash into a stationary lump. The angle between the guns is 120°. Two of the bullets have a mass of 9.30 10-3 kg and are

asked by Anonymous on October 19, 2014
7. physics

A pellet gun is fired straight downward from the edge of a cliff that is 27.1 m above the ground. The pellet strikes the ground with a speed of 25.9 m/s. How far above the cliff edge would the pellet have gone had the gun been

asked by louis aaaa on June 17, 2013
8. phys

A pellet gun is fired straight downward from the edge of a cliff that is 28.5 m above the ground. The pellet strikes the ground with a speed of 26.1 m/s. How far above the cliff edge would the pellet have gone had the gun been

asked by Emily on September 6, 2012
9. physics

A pellet gun is fired straight downward from the edge of a cliff that is 17 m above the ground. The pellet strikes the ground with a speed of 29 m/s. How far above the cliff edge would the pellet have gone had the gun been fired

asked by Sean on October 1, 2010
10. physics

A pellet gun is fired straight downward from the edge of a cliff that is 13.4 m above the ground. The pellet strikes the ground with a speed of 26.1 m/s. How far above the cliff edge would the pellet have gone had the gun been

asked by Katy on September 15, 2013

More Similar Questions
{"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0}