Ball collision time with ceiling

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I know to to do collision time with the ground.
Here's how I calculate that: gravityY = positive 9.81
float timeToGround = (velocity.y + Sqrt(velocity.y*velocity.y + 2f * gravityY * distanceToGround)) / gravityY;
How do I calculate the collision time to the roof/ceiling based on distance and initial velocity?
float timeToRoof = ?
I don't know where to look, thanks so much for your help
math collision gravity
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up vote
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I know to to do collision time with the ground.
Here's how I calculate that: gravityY = positive 9.81
float timeToGround = (velocity.y + Sqrt(velocity.y*velocity.y + 2f * gravityY * distanceToGround)) / gravityY;
How do I calculate the collision time to the roof/ceiling based on distance and initial velocity?
float timeToRoof = ?
I don't know where to look, thanks so much for your help
math collision gravity
New contributor
Sami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Hi there, welcome to SO. I think your question needs a bit of clarification: is gravityY maintained as a vector? (i.e. if it is +9.81 when falling to the ground, will it be -9.81 when rising to the roof?) What isvelocity
? Is it the initial/final velocity?
– John Law
Nov 8 at 8:52
gravity is constant, -9.81, just flipped - for simplicity. velocity is the current velocity
– Sami
Nov 8 at 10:49
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
I know to to do collision time with the ground.
Here's how I calculate that: gravityY = positive 9.81
float timeToGround = (velocity.y + Sqrt(velocity.y*velocity.y + 2f * gravityY * distanceToGround)) / gravityY;
How do I calculate the collision time to the roof/ceiling based on distance and initial velocity?
float timeToRoof = ?
I don't know where to look, thanks so much for your help
math collision gravity
New contributor
Sami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
I know to to do collision time with the ground.
Here's how I calculate that: gravityY = positive 9.81
float timeToGround = (velocity.y + Sqrt(velocity.y*velocity.y + 2f * gravityY * distanceToGround)) / gravityY;
How do I calculate the collision time to the roof/ceiling based on distance and initial velocity?
float timeToRoof = ?
I don't know where to look, thanks so much for your help
math collision gravity
math collision gravity
New contributor
Sami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
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Sami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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edited Nov 8 at 8:50
f_puras
2,18342231
2,18342231
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asked Nov 8 at 8:31


Sami
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32
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Hi there, welcome to SO. I think your question needs a bit of clarification: is gravityY maintained as a vector? (i.e. if it is +9.81 when falling to the ground, will it be -9.81 when rising to the roof?) What isvelocity
? Is it the initial/final velocity?
– John Law
Nov 8 at 8:52
gravity is constant, -9.81, just flipped - for simplicity. velocity is the current velocity
– Sami
Nov 8 at 10:49
add a comment |
Hi there, welcome to SO. I think your question needs a bit of clarification: is gravityY maintained as a vector? (i.e. if it is +9.81 when falling to the ground, will it be -9.81 when rising to the roof?) What isvelocity
? Is it the initial/final velocity?
– John Law
Nov 8 at 8:52
gravity is constant, -9.81, just flipped - for simplicity. velocity is the current velocity
– Sami
Nov 8 at 10:49
Hi there, welcome to SO. I think your question needs a bit of clarification: is gravityY maintained as a vector? (i.e. if it is +9.81 when falling to the ground, will it be -9.81 when rising to the roof?) What is
velocity
? Is it the initial/final velocity?– John Law
Nov 8 at 8:52
Hi there, welcome to SO. I think your question needs a bit of clarification: is gravityY maintained as a vector? (i.e. if it is +9.81 when falling to the ground, will it be -9.81 when rising to the roof?) What is
velocity
? Is it the initial/final velocity?– John Law
Nov 8 at 8:52
gravity is constant, -9.81, just flipped - for simplicity. velocity is the current velocity
– Sami
Nov 8 at 10:49
gravity is constant, -9.81, just flipped - for simplicity. velocity is the current velocity
– Sami
Nov 8 at 10:49
add a comment |
2 Answers
2
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0
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accepted
You need to solve quadratic equation for unknown time t
h = y0 + Vy * t - g*t^2 / 2
or
g*t^2/2 - Vy*t + (h-y0) = 0 // a,b,c coefficient grouped
for known height of starting point y0, roof height h, gravity g, y-component of initial velocity Vy
wait, isn't this the exact same equation that i provided? am i missing something?
– Sami
Nov 8 at 11:22
Yes, your formula represents solution of this equation for caseh=0, y0 = distanceToGround
. You can slightly correct it for you current task (that has not been properly formulated yet)
– MBo
Nov 8 at 11:37
It's the same suvat formula, the same general principle; but you substitute ing = -9.81
(negative acceleration, instead of positive) andh - y0 = distanceToRoof
, so it's still different in some respects.
– John Law
Nov 8 at 17:27
add a comment |
up vote
0
down vote
Hehe, thanks for your help.
Here's the answer:
float timeToRoof = (-velocity.y + Sqrt(velocity.y * velocity.y + 2f * gravity.y * distanceToRoof)) / gravity.y;
- gravity.y = negative -9.81
- velocity.y = current velocity
- distanceToRoof = current distance to roof
New contributor
Sami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
0
down vote
accepted
You need to solve quadratic equation for unknown time t
h = y0 + Vy * t - g*t^2 / 2
or
g*t^2/2 - Vy*t + (h-y0) = 0 // a,b,c coefficient grouped
for known height of starting point y0, roof height h, gravity g, y-component of initial velocity Vy
wait, isn't this the exact same equation that i provided? am i missing something?
– Sami
Nov 8 at 11:22
Yes, your formula represents solution of this equation for caseh=0, y0 = distanceToGround
. You can slightly correct it for you current task (that has not been properly formulated yet)
– MBo
Nov 8 at 11:37
It's the same suvat formula, the same general principle; but you substitute ing = -9.81
(negative acceleration, instead of positive) andh - y0 = distanceToRoof
, so it's still different in some respects.
– John Law
Nov 8 at 17:27
add a comment |
up vote
0
down vote
accepted
You need to solve quadratic equation for unknown time t
h = y0 + Vy * t - g*t^2 / 2
or
g*t^2/2 - Vy*t + (h-y0) = 0 // a,b,c coefficient grouped
for known height of starting point y0, roof height h, gravity g, y-component of initial velocity Vy
wait, isn't this the exact same equation that i provided? am i missing something?
– Sami
Nov 8 at 11:22
Yes, your formula represents solution of this equation for caseh=0, y0 = distanceToGround
. You can slightly correct it for you current task (that has not been properly formulated yet)
– MBo
Nov 8 at 11:37
It's the same suvat formula, the same general principle; but you substitute ing = -9.81
(negative acceleration, instead of positive) andh - y0 = distanceToRoof
, so it's still different in some respects.
– John Law
Nov 8 at 17:27
add a comment |
up vote
0
down vote
accepted
up vote
0
down vote
accepted
You need to solve quadratic equation for unknown time t
h = y0 + Vy * t - g*t^2 / 2
or
g*t^2/2 - Vy*t + (h-y0) = 0 // a,b,c coefficient grouped
for known height of starting point y0, roof height h, gravity g, y-component of initial velocity Vy
You need to solve quadratic equation for unknown time t
h = y0 + Vy * t - g*t^2 / 2
or
g*t^2/2 - Vy*t + (h-y0) = 0 // a,b,c coefficient grouped
for known height of starting point y0, roof height h, gravity g, y-component of initial velocity Vy
answered Nov 8 at 8:54
MBo
44.7k22847
44.7k22847
wait, isn't this the exact same equation that i provided? am i missing something?
– Sami
Nov 8 at 11:22
Yes, your formula represents solution of this equation for caseh=0, y0 = distanceToGround
. You can slightly correct it for you current task (that has not been properly formulated yet)
– MBo
Nov 8 at 11:37
It's the same suvat formula, the same general principle; but you substitute ing = -9.81
(negative acceleration, instead of positive) andh - y0 = distanceToRoof
, so it's still different in some respects.
– John Law
Nov 8 at 17:27
add a comment |
wait, isn't this the exact same equation that i provided? am i missing something?
– Sami
Nov 8 at 11:22
Yes, your formula represents solution of this equation for caseh=0, y0 = distanceToGround
. You can slightly correct it for you current task (that has not been properly formulated yet)
– MBo
Nov 8 at 11:37
It's the same suvat formula, the same general principle; but you substitute ing = -9.81
(negative acceleration, instead of positive) andh - y0 = distanceToRoof
, so it's still different in some respects.
– John Law
Nov 8 at 17:27
wait, isn't this the exact same equation that i provided? am i missing something?
– Sami
Nov 8 at 11:22
wait, isn't this the exact same equation that i provided? am i missing something?
– Sami
Nov 8 at 11:22
Yes, your formula represents solution of this equation for case
h=0, y0 = distanceToGround
. You can slightly correct it for you current task (that has not been properly formulated yet)– MBo
Nov 8 at 11:37
Yes, your formula represents solution of this equation for case
h=0, y0 = distanceToGround
. You can slightly correct it for you current task (that has not been properly formulated yet)– MBo
Nov 8 at 11:37
It's the same suvat formula, the same general principle; but you substitute in
g = -9.81
(negative acceleration, instead of positive) and h - y0 = distanceToRoof
, so it's still different in some respects.– John Law
Nov 8 at 17:27
It's the same suvat formula, the same general principle; but you substitute in
g = -9.81
(negative acceleration, instead of positive) and h - y0 = distanceToRoof
, so it's still different in some respects.– John Law
Nov 8 at 17:27
add a comment |
up vote
0
down vote
Hehe, thanks for your help.
Here's the answer:
float timeToRoof = (-velocity.y + Sqrt(velocity.y * velocity.y + 2f * gravity.y * distanceToRoof)) / gravity.y;
- gravity.y = negative -9.81
- velocity.y = current velocity
- distanceToRoof = current distance to roof
New contributor
Sami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
up vote
0
down vote
Hehe, thanks for your help.
Here's the answer:
float timeToRoof = (-velocity.y + Sqrt(velocity.y * velocity.y + 2f * gravity.y * distanceToRoof)) / gravity.y;
- gravity.y = negative -9.81
- velocity.y = current velocity
- distanceToRoof = current distance to roof
New contributor
Sami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
up vote
0
down vote
up vote
0
down vote
Hehe, thanks for your help.
Here's the answer:
float timeToRoof = (-velocity.y + Sqrt(velocity.y * velocity.y + 2f * gravity.y * distanceToRoof)) / gravity.y;
- gravity.y = negative -9.81
- velocity.y = current velocity
- distanceToRoof = current distance to roof
New contributor
Sami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Hehe, thanks for your help.
Here's the answer:
float timeToRoof = (-velocity.y + Sqrt(velocity.y * velocity.y + 2f * gravity.y * distanceToRoof)) / gravity.y;
- gravity.y = negative -9.81
- velocity.y = current velocity
- distanceToRoof = current distance to roof
New contributor
Sami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Sami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 2 days ago


Sami
32
32
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New contributor
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Check out our Code of Conduct.
Sami is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
add a comment |
Sami is a new contributor. Be nice, and check out our Code of Conduct.
Sami is a new contributor. Be nice, and check out our Code of Conduct.
Sami is a new contributor. Be nice, and check out our Code of Conduct.
Sami is a new contributor. Be nice, and check out our Code of Conduct.
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Hi there, welcome to SO. I think your question needs a bit of clarification: is gravityY maintained as a vector? (i.e. if it is +9.81 when falling to the ground, will it be -9.81 when rising to the roof?) What is
velocity
? Is it the initial/final velocity?– John Law
Nov 8 at 8:52
gravity is constant, -9.81, just flipped - for simplicity. velocity is the current velocity
– Sami
Nov 8 at 10:49