# Help me to solve this

#### nascx

##### New member
Help me to solve this update

The dog ringo loves sticks thrown into the water, she usually jumps from rocks to retrieve it.

f (x) = - 0.3X^2 + x + 2.5

Ringo jumps into the water from a 1m high cliff over the lake. Ringo jump time is 3second then after 1second at the highest altitude 1.33m above the lake.

a) Determine the quadratic equation for Ringo's path across the lake. Where x seconds is the time for the dog's air travel and y m height.

b) How far must ringo swim to retrieve the stick if her jump length is 2.5m

Last edited:

#### tkhunny

##### Moderator
Staff member
The dog ringo loves sticks thrown into the water, she usually jumps from rocks to retrieve it.

f (x) = - 0.3X + 2 + x + 2.5

Ringo jumps into the water from a 1m high cliff over the lake. Ringo jump time is 3s then she was after 1s at the highest altitude 1.33m above the lake.

a) Determine the quadratic equation for Ringo's path across the lake. Where x seconds the time for the dog's air travel and y m height.

b) How far must ringo swim to retrieve the stick if her jump length is 2.5m
1) Your f(x) may not make any sense. Please check to see if you have presented it correctly. Maybe, f(x) = -0.3x^2 + x + 2.5?
2) How does f(x) relate to the problem statement? Is that the path of the stick.
3) I suppose we are to assume that neither the stick nor the dog have any horizontal velocity when they each hit the water?

#### Dr.Peterson

##### Elite Member
The dog ringo loves sticks thrown into the water, she usually jumps from rocks to retrieve it.

f (x) = - 0.3X + 2 + x + 2.5

Ringo jumps into the water from a 1m high cliff over the lake. Ringo jump time is 3s then she was after 1s at the highest altitude 1.33m above the lake.

a) Determine the quadratic equation for Ringo's path across the lake. Where x seconds the time for the dog's air travel and y m height.

b) How far must ringo swim to retrieve the stick if her jump length is 2.5m
This will need some corrections and clarifications.

First, you haven't said what f represents; is f(x) the height at time x seconds? But you are asked to find an equation, so this must be something else (in addition to not being quadratic). Is it the path of the stick?

Second, it is unclear what "jump time" or "jump length" refer to.

Third, as I read it, nothing has been said about horizontal distances, since x is time; so how can we know how far the dog has to swim?

Please copy (translate?) the problem as exactly as you can, and use extra words to explain anything that is not clear.

#### nascx

##### New member
This will need some corrections and clarifications.

First, you haven't said what f represents; is f(x) the height at time x seconds? But you are asked to find an equation, so this must be something else (in addition to not being quadratic). Is it the path of the stick?

Second, it is unclear what "jump time" or "jump length" refer to.

Third, as I read it, nothing has been said about horizontal distances, since x is time; so how can we know how far the dog has to swim?

Please copy (translate?) the problem as exactly as you can, and use extra words to explain anything that is not clear.

I've edited the question and tried to translate it as good as i can you think you can help me solve this problem?

#### topsquark

##### Full Member
Assuming that the stick's equation of motion is f(x) (where x represents time and does f(x) represent the horizontal displacement?), do the dog and the stick hit the water at the same time and place?

-Dan

#### Dr.Peterson

##### Elite Member
The dog ringo loves sticks thrown into the water, she usually jumps from rocks to retrieve it.

f (x) = - 0.3X^2 + x + 2.5

Ringo jumps into the water from a 1m high cliff over the lake. Ringo jump time is 3second then after 1second at the highest altitude 1.33m above the lake.

a) Determine the quadratic equation for Ringo's path across the lake. Where x seconds is the time for the dog's air travel and y m height.

b) How far must ringo swim to retrieve the stick if her jump length is 2.5m
I see that you corrected the equation, but you haven't answered the other questions.

We need to know:

• whether f(x) is the height of the stick or the dog or something else, and whether that x, like the other, is time;
• whether "Ringo's jump time" means the time until he hits the water, or the time after the stick is thrown, or something else;
• what is known about horizontal motion of the stick, if the 2.5 m is the distance at which the dog hits the water.

#### nascx

##### New member
Assuming that the stick's equation of motion is f(x) (where x represents time and does f(x) represent the horizontal displacement?), do the dog and the stick hit the water at the same time and place?

-Dan
Ringo loves sticks thrown into the water, she usually jumps from cliffs to retrieve the stick's air travel

can be described by the forumla

i guess the stick hit the water first then the dog.