Kinematics: Understanding the Range Formula

[ThomasMagnus]

For a kinematics question, I am using the range formula:

R=(Vo^2)(Sin2(theta))/(g)

With my values in the equation I get: Square root of((7.80)(9.80)/(Sin2(28))
The correct answer is 9.60. I can't seem to get this answer. I believe it is the "Sin2(28)" part. What does this mean? Does this mean sin56? 2xsin28? Would you be able to explain what this means?

Thanks!

 

[gneill]

It means,

$$Range = \frac{V_o^2 \; sin(2 \theta)}{g}$$

 

[ThomasMagnus]

Sorry, I'm having trouble understanding. This kind of set up is new to me. I can't seem to get the correct answer when I plug it into my calculator. Does it have anything to do with the calculator being in radian or degree mode?

Thanks!

 

[ThomasMagnus]

When I do it, I get 8.84, but the correct answer is supposedly 9.60

 

[ThomasMagnus]

What I am asking is: how do you evaluate sin2(28)?

Thanks

 

[gneill]

What I am asking is: how do you evaluate sin2(28)?

Thanks

sin(2 * 28 degrees) = 0.829

 

[ThomasMagnus]

sin(2 * 28 degrees) = 0.829

What would be the keystrokes for the calculator?

Thanks!

 

[ThomasMagnus]

Wait I got it :)

Sin(2x28)=0.829

Thanks for the help!