# Thread: Angle and Initial Velocity Problem

1. ## Angle and Initial Velocity Problem

A collegiate javelin thrower releases the javelin at a 40 degree angle, with an initial velocity of about 95ft/sec.

A) If the NCAA record is 280 ft, will she break this record?
B) What is the smallest angle of release that will break this record?
C) If the javelin were released at the optimum 45 degree, by how many feet would the record be broken.

2. ## Re: Angle and Initial Velocity Problem

What, exactly, is your question? How can you look at this problem and immediately know the answer, without doing any calculation at all? Can't help you there because I certain couldn't do that! I do know of several different ways to do this problem but I don't know which is appropriate for you because I don't know what "tools" you have available! The simplest would be if you know the formula: if an object has initial speed v at angle $\theta$ with the horizontal, they the distance it goes in time t is $x= v cos(\theta)t$ and the height in that same time is $y= v sin(\theta) t- (g/2)t^2$ where "g" is the acceleration due to gravity: 32.2 feet per second per second.

The distance the javelin will travel is the x value when y is again 0.
For (C) do the same using 45 degrees instead of 40 degrees.
For (B) do the calculation with the variable " $\theta$" still in it. Set the x distance, when y= 0, equal to 280 and solve for $\theta$.

3. ## Re: Angle and Initial Velocity Problem

Originally Posted by ticaaal70
A collegiate javelin thrower releases the javelin at a 40 degree angle, with an initial velocity of about 95ft/sec.

A) If the NCAA record is 280 ft, will she break this record?
B) What is the smallest angle of release that will break this record?
C) If the javelin were released at the optimum 45 degree, by how many feet would the record be broken.