# Infinity Question (some physics background)

#### PatrickDinehart

##### New Member
I have a noobish question but I haven't been able to figure it out. In physics, we did a design lab (make a lab up on the spot and do it) and I was trying to calculate the correlation between the angle of a ramp to the acceleration of a car that went down the ramp. Of course, we are at the beginning of the year so we're limited to simple kinematics and derivatives/integrals. At a ramp of 0 degrees, the time for the car to go down it is infinite and thus, the acceleration would be calculated under the following premises:

X=x0 + vot + (1/2)a(t^2)

To make this plug able into Excel, I moved a (acceleration) to one side of the equation and plugged in x, x0, v0, and t. The problem here is t is infinite. For reference, the equation ended up being: =0.5*((0+0*(C8)+(C8^2))/1.0385) where C8 is the AVG Time (5 trials 5 times ect).

Is it possible I have used the wrong infinity symbol or is this simply incalculable?

Patrick

### Excel Facts

Create a chart in one keystroke
Select the data and press Alt+F1 to insert a default chart. You can change the default chart to any chart type

#### ranman256

##### Well-known Member
I dont think the infinity symbol has a value in Excel.

#### shg

##### MrExcel MVP
The car doesn't take an infinite amount of time to go down the ramp when the slope is zero; the time increases without limit ('approaches infinity') as the slope of the ramp decreases toward zero:

Programming languages don't know about infinity.

Last edited:

#### shg

##### MrExcel MVP
The acceleration of the car is the acceleration of gravity times the sine of the slope:

 A​ B​ C​ D​ 1​ Slope [deg]​ -5​ B1: Input 2​ accel [m/s/s]​ -0.854​ B2: =9.8*SIN(RADIANS(B1)) 3​ 4​ v0 [m/s]​ x0 [m/s]​ 5​ 0​ 0​ 6​ t​
[td]
v [m/s]​
[/td][td]
x [m]​
[/td][td][/td]

[tr][td]
7​
[/td][td]
0​
[/td][td]
0.00​
[/td][td]
0.00​
[/td][td]B7: =\$B\$2*A7[/td][/tr]

[tr][td]
8​
[/td][td]
1​
[/td][td]
-0.85​
[/td][td]
-0.43​
[/td][td]C7: =\$C\$5 + \$B\$5*A7 + \$B\$2*A7^2/2[/td][/tr]

[tr][td]
9​
[/td][td]
2​
[/td][td]
-1.71​
[/td][td]
-1.71​
[/td][td][/td][/tr]

[tr][td]
10​
[/td][td]
3​
[/td][td]
-2.56​
[/td][td]
-3.84​
[/td][td][/td][/tr]

[tr][td]
11​
[/td][td]
4​
[/td][td]
-3.42​
[/td][td]
-6.83​
[/td][td][/td][/tr]

[tr][td]
12​
[/td][td]
5​
[/td][td]
-4.27​
[/td][td]
-10.68​
[/td][td][/td][/tr]

[tr][td]
13​
[/td][td]
6​
[/td][td]
-5.12​
[/td][td]
-15.37​
[/td][td][/td][/tr]

[tr][td]
14​
[/td][td]
7​
[/td][td]
-5.98​
[/td][td]
-20.93​
[/td][td][/td][/tr]

[tr][td]
15​
[/td][td]
8​
[/td][td]
-6.83​
[/td][td]
-27.33​
[/td][td][/td][/tr]

#### PatrickDinehart

##### New Member
The acceleration of the car is the acceleration of gravity times the sine of the slope:

 A​ B​ C​ D​ 1​ Slope [deg]​ -5​ B1: Input 2​ accel [m/s/s]​ -0.854​ B2: =9.8*SIN(RADIANS(B1)) 3​ 4​ v0 [m/s]​ x0 [m/s]​ 5​ 0​ 0​ 6​ t​

<tbody>
[TD]
v [m/s]​
[/TD]
[TD]
x [m]​
[/TD]
[TD][/TD]

[TR]
[TD]
7​
[/TD]
[TD]
0​
[/TD]
[TD]
0.00​
[/TD]
[TD]
0.00​
[/TD]
[TD]B7: =\$B\$2*A7[/TD]
[/TR]
[TR]
[TD]
8​
[/TD]
[TD]
1​
[/TD]
[TD]
-0.85​
[/TD]
[TD]
-0.43​
[/TD]
[TD]C7: =\$C\$5 + \$B\$5*A7 + \$B\$2*A7^2/2[/TD]
[/TR]
[TR]
[TD]
9​
[/TD]
[TD]
2​
[/TD]
[TD]
-1.71​
[/TD]
[TD]
-1.71​
[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]
10​
[/TD]
[TD]
3​
[/TD]
[TD]
-2.56​
[/TD]
[TD]
-3.84​
[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]
11​
[/TD]
[TD]
4​
[/TD]
[TD]
-3.42​
[/TD]
[TD]
-6.83​
[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]
12​
[/TD]
[TD]
5​
[/TD]
[TD]
-4.27​
[/TD]
[TD]
-10.68​
[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]
13​
[/TD]
[TD]
6​
[/TD]
[TD]
-5.12​
[/TD]
[TD]
-15.37​
[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]
14​
[/TD]
[TD]
7​
[/TD]
[TD]
-5.98​
[/TD]
[TD]
-20.93​
[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]
15​
[/TD]
[TD]
8​
[/TD]
[TD]
-6.83​
[/TD]
[TD]
-27.33​
[/TD]
[TD][/TD]
[/TR]
</tbody>

Thanks for the replies so far! On a second note, can you explain the table? We don't necessarily use slopes on the understanding that delta(velocity, position, or acceleration) will be the slope in question.

#### shg

##### MrExcel MVP
The slope of the ramp determines the accelerating force on the car, no?

EDIT: Describe your experiment; what you do, what you record, and what result you're trying to calculate.

Last edited:

#### PatrickDinehart

##### New Member
The slope of the ramp determines the accelerating force on the car, no?

EDIT: Describe your experiment; what you do, what you record, and what result you're trying to calculate.

To your first question: Yes, although we can't just say "slope is 3 therefore A must be 3". We have to use kinematics to prove it. Why, I don't know but thus is life. After looking at the chart, I understand it. It took me a minute because of curriculum changes over the last year :D Thanks again!

So -- sorted?

1,195,624
Messages
6,010,751
Members
441,568
Latest member
abbyabby

### We've detected that you are using an adblocker.

We have a great community of people providing Excel help here, but the hosting costs are enormous. You can help keep this site running by allowing ads on MrExcel.com.

### Which adblocker are you using?

1)Click on the icon in the browser’s toolbar.
2)Click on the icon in the browser’s toolbar.
2)Click on the "Pause on this site" option.
Go back

1)Click on the icon in the browser’s toolbar.
2)Click on the toggle to disable it for "mrexcel.com".
Go back

### Disable uBlock Origin

Follow these easy steps to disable uBlock Origin

1)Click on the icon in the browser’s toolbar.
2)Click on the "Power" button.
3)Click on the "Refresh" button.
Go back

### Disable uBlock

Follow these easy steps to disable uBlock

1)Click on the icon in the browser’s toolbar.
2)Click on the "Power" button.
3)Click on the "Refresh" button.
Go back