Hovercraft B/C

[HandsFreeCookieDunk]

I guess I'll go to the physics side.

A cylindrical water tank has a small hole in its side through which water is spurting. The hole is 5m above the ground and 1m below the surface of the water. For simplicity's sake, assume the water level in the tank is not dropping. How far horizontally does the water travel before hitting the ground?

[sciduck]

I guess I'll go to the physics side.

A cylindrical water tank has a small hole in its side through which water is spurting. The hole is 5m above the ground and 1m below the surface of the water. For simplicity's sake, assume the water level in the tank is not dropping. How far horizontally does the water travel before hitting the ground?

Do I show work? (Click to Show Hidden Text)

From Bernoulli's principle, I get a velocity of 4.427 m/s.
Let's say that's horizontal velocity, so initial vertical velocity is 0 m/s.
So it'll take 1.01015 s to hit the ground.
No horizontal velocity --> 4.47 m.
Uhhh, 1 sigfig? So ~4m.

[HandsFreeCookieDunk]

I guess I'll go to the physics side.

A cylindrical water tank has a small hole in its side through which water is spurting. The hole is 5m above the ground and 1m below the surface of the water. For simplicity's sake, assume the water level in the tank is not dropping. How far horizontally does the water travel before hitting the ground?

Do I show work? (Click to Show Hidden Text)

From Bernoulli's principle, I get a velocity of 4.427 m/s.
Let's say that's horizontal velocity, so initial vertical velocity is 0 m/s.
So it'll take 1.01015 s to hit the ground.
No horizontal velocity --> 4.6047 m.
Uhhh, 1 sigfig? So ~5m.

Yeah, sorry about the sigfigs, I was just throwing numbers at it. I was with you until the final step, where x = vt = 4.427 m/s * 1.01015s = 4.472m

[sciduck]

I guess I'll go to the physics side.

A cylindrical water tank has a small hole in its side through which water is spurting. The hole is 5m above the ground and 1m below the surface of the water. For simplicity's sake, assume the water level in the tank is not dropping. How far horizontally does the water travel before hitting the ground?

Do I show work? (Click to Show Hidden Text)

From Bernoulli's principle, I get a velocity of 4.427 m/s.
Let's say that's horizontal velocity, so initial vertical velocity is 0 m/s.
So it'll take 1.01015 s to hit the ground.
No horizontal velocity --> 4.6047 m.
Uhhh, 1 sigfig? So ~5m.

Yeah, sorry about the sigfigs, I was just throwing numbers at it. I was with you until the final step, where x = vt = 4.427 m/s * 1.01015s = 4.472m

Oops, I typed it in my calculator wrong ;a;

Next question: Say you are standing on top of a building and threw a ball A downward with a velocity -v, and threw a different ball B (from the same height) upward with a velocity of v. Then:
A) A will hit the ground with a velocity greater than B's.
B) B will hit the ground with a velocity greater than A's.
C) Both hit the ground at the same speed.
D) Neither of the balls will hit the ground.

[Zioly]

Do I show work? (Click to Show Hidden Text)

From Bernoulli's principle, I get a velocity of 4.427 m/s.
Let's say that's horizontal velocity, so initial vertical velocity is 0 m/s.
So it'll take 1.01015 s to hit the ground.
No horizontal velocity --> 4.6047 m.
Uhhh, 1 sigfig? So ~5m.

Yeah, sorry about the sigfigs, I was just throwing numbers at it. I was with you until the final step, where x = vt = 4.427 m/s * 1.01015s = 4.472m

Oops, I typed it in my calculator wrong ;a;

Next question: Say you are standing on top of a building and threw a ball A downward with a velocity -v, and threw a different ball B (from the same height) upward with a velocity of v. Then:
A) A will hit the ground with a velocity greater than B's.
B) B will hit the ground with a velocity greater than A's.
C) Both hit the ground at the same speed.
D) Neither of the balls will hit the ground.

Answer (Click to Show Hidden Text)

B will hit the ground with a velocity greater than A's, as B will attain a negative velocity, and thus head towards the ground, at a higher starting point than A. Thus, the extra distance needed to be traversed gives ball B a bit more time to accelerate due to gravity.

EDIT: hid the answer
EDIT 2: my answer's wrong. I had a brainfart when I mistook ball A's initial velocity as a simple drop and therefore 0 m/s. HandsFreeCookieDunk's explanation with the energies allowed me to realize my mistake. Sorry 'bout that.

[HandsFreeCookieDunk]

Do I show work? (Click to Show Hidden Text)

From Bernoulli's principle, I get a velocity of 4.427 m/s.
Let's say that's horizontal velocity, so initial vertical velocity is 0 m/s.
So it'll take 1.01015 s to hit the ground.
No horizontal velocity --> 4.6047 m.
Uhhh, 1 sigfig? So ~5m.

Yeah, sorry about the sigfigs, I was just throwing numbers at it. I was with you until the final step, where x = vt = 4.427 m/s * 1.01015s = 4.472m

Oops, I typed it in my calculator wrong ;a;

Next question: Say you are standing on top of a building and threw a ball A downward with a velocity -v, and threw a different ball B (from the same height) upward with a velocity of v. Then:
A) A will hit the ground with a velocity greater than B's.
B) B will hit the ground with a velocity greater than A's.
C) Both hit the ground at the same speed.
D) Neither of the balls will hit the ground.

Answer (Click to Show Hidden Text)

The answer is C. Because the two balls have the same initial total energy (gravitational potential+kinetic) they will have the same kinetic energy when gravitational potential energy is 0 and will therefore have the same velocity. Lol at answer D though.  :lol:

[Ashernoel]

Do I show work? (Click to Show Hidden Text)

From Bernoulli's principle, I get a velocity of 4.427 m/s.
Let's say that's horizontal velocity, so initial vertical velocity is 0 m/s.
So it'll take 1.01015 s to hit the ground.
No horizontal velocity --> 4.6047 m.
Uhhh, 1 sigfig? So ~5m.

Yeah, sorry about the sigfigs, I was just throwing numbers at it. I was with you until the final step, where x = vt = 4.427 m/s * 1.01015s = 4.472m

Oops, I typed it in my calculator wrong ;a;

Next question: Say you are standing on top of a building and threw a ball A downward with a velocity -v, and threw a different ball B (from the same height) upward with a velocity of v. Then:
A) A will hit the ground with a velocity greater than B's.
B) B will hit the ground with a velocity greater than A's.
C) Both hit the ground at the same speed.
D) Neither of the balls will hit the ground.

Answer (Click to Show Hidden Text)

Answer: 
C. 
Velocity is a vector, and by throwing A down with -v, it can be translated to upward with v, the same as B. then due to acceleration due to gravity, both will follow the same trajectory and hit the ground at the same time

[kenniky]

Yeah, sorry about the sigfigs, I was just throwing numbers at it. I was with you until the final step, where x = vt = 4.427 m/s * 1.01015s = 4.472m

Oops, I typed it in my calculator wrong ;a;

Next question: Say you are standing on top of a building and threw a ball A downward with a velocity -v, and threw a different ball B (from the same height) upward with a velocity of v. Then:
A) A will hit the ground with a velocity greater than B's.
B) B will hit the ground with a velocity greater than A's.
C) Both hit the ground at the same speed.
D) Neither of the balls will hit the ground.

title (Click to Show Hidden Text)

C. 
Velocity is a vector, and by throwing A down with -v, it can be translated to upward with v, the same as B. then due to acceleration due to gravity, both will follow the same trajectory and hit the ground at the same time

You gotta have a title to your [ hide] lol

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[hide] title | stuff [/hide]

title (Click to Show Hidden Text)

stuff

Otherwise it breaks :p

[Ashernoel]

title (Click to Show Hidden Text)

thanks for the help, this is pretty sick :p

[sciduck]

Yeah, sorry about the sigfigs, I was just throwing numbers at it. I was with you until the final step, where x = vt = 4.427 m/s * 1.01015s = 4.472m

Oops, I typed it in my calculator wrong ;a;

Next question: Say you are standing on top of a building and threw a ball A downward with a velocity -v, and threw a different ball B (from the same height) upward with a velocity of v. Then:
A) A will hit the ground with a velocity greater than B's.
B) B will hit the ground with a velocity greater than A's.
C) Both hit the ground at the same speed.
D) Neither of the balls will hit the ground.

Answer (Click to Show Hidden Text)

The answer is C. Because the two balls have the same initial total energy (gravitational potential+kinetic) they will have the same kinetic energy when gravitational potential energy is 0 and will therefore have the same velocity. Lol at answer D though.  :lol:

Yup! I lost track of turns, but go for it.