Solve Shot Put Launch Angle Homework: Speed 15.1m/s

In summary, to find the initial speed of the shot that set the men's world record for shot put, we can use the horizontal range equation to find the initial velocity in the x-direction, the vertical range equation to solve for the time it takes for the shot to reach the ground, and then use the horizontal range equation again to solve for the initial speed. The initial speed was 44.05m/s.
  • #1
Rhoadsb
1
0

Homework Statement



The men's world record for the shot put, 23.12m, was set by Randy Barnes of the United States on May 20, 1990. If the shot was launched from 6.00ft above the ground at an initial angle of 42.0o, what was its initial speed?

Homework Equations


R=2(Vo^2/g)Sin(theta)Cos(theta)
x=Voxt
Tmax= Voy/g
Ttot=2Voy/g


The Attempt at a Solution



Initially, I solved for Vo in the range equation, and I came up with 23.12=2(Vo^2/g)sin(42)cos(42)= 15.1 m/s
I know I need to break it up into x and y components, but I'm not really sure how without any Vxo, time, or Vo.
 
Physics news on Phys.org
  • #2


Hello,

To solve for the initial speed (Vo), we can use the horizontal range equation, which is x = Vx * t. Since we know the initial angle (42 degrees) and the initial height (6.00ft), we can use trigonometry to find the initial velocity in the x-direction (Vx). We can use the formula Vx = Vo * cos(theta), where theta is the initial angle. So, Vx = Vo * cos(42) = Vo * 0.7431.

Next, we can use the vertical range equation to solve for the time (t) it takes for the shot to reach the ground. The vertical range equation is y = Voy * t - (1/2) * g * t^2. Since the shot starts at 6.00ft above the ground and ends at ground level (0ft), we can set y = -6.00ft and solve for t. This gives us the equation -6.00 = Voy * t - (1/2) * 9.8 * t^2. We can rearrange this to t^2 - (2 * Voy / 9.8) * t + 1.2245 = 0. Using the quadratic formula, we can solve for t, which gives us two values: t = 0.215s and t = 5.677s. Since the shot is in the air for a much shorter time than 5.677s, we can assume that the correct value for t is 0.215s.

Now that we have the time (t) and the initial velocity in the x-direction (Vx), we can use the horizontal range equation to solve for the initial speed (Vo). Plugging in the values we know, we get 23.12m = Vx * t = (Vo * 0.7431) * 0.215, which gives us Vo = 44.05m/s.

Therefore, the initial speed of the shot was 44.05m/s. I hope this helps!
 
  • #3


I would approach this problem by first identifying the known variables and what is being asked for. The known variables are the initial angle of the shot (42.0o), the initial speed (15.1m/s), and the height from which the shot was launched (6.00ft). The unknown variable is the initial speed at which the shot was launched.

To solve for the initial speed, we can use the equation R=2(Vo^2/g)Sin(theta)Cos(theta), where R is the range, Vo is the initial speed, g is the acceleration due to gravity, and theta is the launch angle. We can rearrange this equation to solve for Vo:

Vo = √(Rg/2sin(theta)cos(theta))

Plugging in the known values, we get:

Vo = √(23.12m * 9.8m/s^2 / 2 * sin(42.0o) * cos(42.0o)) = 15.1 m/s

Therefore, the initial speed of the shot was 15.1 m/s. This is consistent with the given initial speed in the homework statement, so our solution is correct.

To break it down into x and y components, we can use the equations x=Voxt and Ttot=2Voy/g. Since we are only given the initial speed and launch angle, we cannot determine the time of flight or the x component of the velocity. However, we can calculate the y component of the velocity using the equation Tmax= Voy/g:

Tmax = 2Voy/g

Solving for Voy, we get:

Voy = g * Tmax/2 = 9.8 m/s^2 * 6.00ft / 2 = 14.7 m/s

Therefore, the initial y component of the velocity is 14.7 m/s. This can also be used to calculate the time of flight using the equation Ttot=2Voy/g.

In conclusion, the initial speed of the shot was 15.1 m/s and the initial y component of the velocity was 14.7 m/s. More information, such as the time of flight or the x component of the velocity, would be needed to fully solve this problem.
 

Related to Solve Shot Put Launch Angle Homework: Speed 15.1m/s

1) What is the formula for calculating the launch angle in shot put?

The formula for calculating the launch angle in shot put is: θ = arcsin (2gh/v2) where θ is the launch angle, g is the acceleration due to gravity, h is the height of release, and v is the initial velocity.

2) How can I determine the initial velocity in shot put?

The initial velocity in shot put can be determined by dividing the total distance of the throw by the time it takes for the shot to travel that distance. In this case, the initial velocity is 15.1m/s.

3) What is the significance of the launch angle in shot put?

The launch angle in shot put determines the trajectory of the shot and ultimately, the distance it will travel. A higher launch angle can result in a longer throw, but requires more strength and may be harder to control.

4) How does the speed of the shot affect the launch angle in shot put?

The speed of the shot, in this case 15.1m/s, directly affects the launch angle. A higher initial velocity will result in a lower launch angle, while a lower initial velocity will result in a higher launch angle. This is because a higher velocity requires less of an angle to achieve a longer distance.

5) How can I improve my launch angle in shot put?

To improve your launch angle in shot put, you can work on increasing your speed and power in your throw, as well as practicing proper technique. Additionally, working on your flexibility and range of motion can also help improve your launch angle. It is important to consult with a coach or trainer for specific techniques and exercises to improve your launch angle.

Similar threads

  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
10
Views
3K
  • Introductory Physics Homework Help
Replies
16
Views
4K
  • Introductory Physics Homework Help
Replies
8
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
2K
Replies
25
Views
2K
  • Introductory Physics Homework Help
Replies
2
Views
2K
  • Introductory Physics Homework Help
Replies
6
Views
6K
  • Introductory Physics Homework Help
Replies
8
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
3K
Back
Top