Calculate Angle & Speed of Rock Launched from Cliff Catapult

  • Thread starter booneyromper
  • Start date
  • Tags
    Catapult
In summary, a catapult on a cliff launches a large round rock towards a ship on the ocean below. The rock is launched from a height of 34.0m above sea level at an angle above the horizontal with an initial speed of 37.47 m/s. The projectile remains in flight for 6.00 seconds and travels a horizontal distance of 174m. The angle of launch is approximately 39.29 degrees.
  • #1
booneyromper
2
0
A catapult on a cliff launches a large round rock towards a ship on the ocean below. The rock leaves the catapult from a height H of 34.0m above sea level, directed at an angle above the horizontal with an unknown speed. The projectile remains in flight for 6.00 seconds and travels a horizontal distance of 174m. Assuming that air friction can be neglected, calculate the value of the angle (in degrees). Also calculate the speed at which the rock is launched.

My brains are cooked. I'm not sure where to begin with this one.
 
Physics news on Phys.org
  • #2
Cooked brains or not, please show your reasoning and lots of working. :smile:

What are the equations governing the motion of a projectile ?
 
  • #3
Thanks for the hint. I took a break, ate dinner, shook off the frustration, then came back and solved the problem
For horizontal velocity X = Xo + (Vxo)t,
174m = 0+(Vxo)6.00s,
Vxo = 29 m/s
For vertical velocity Y = Yo + (Vyo)T - 1/2gt^2,
-34m = (Vyo)6.00s - (1/2)(9.8m/s^2)(6.00s^2)
Vyo = 23.73m/s
So the angle theta = tan-1 (23.73/29) = 39.29deg
and the rock is launched at... Square root of (29^2 + 23.73^2) = 37.47

The moral of the story is don't do physics on an empty stomach.
 

1. How do you calculate the angle and speed of a rock launched from a cliff catapult?

The angle and speed of a rock launched from a cliff catapult can be calculated using the equations of projectile motion. This involves taking into account the initial velocity, angle of launch, and acceleration due to gravity.

2. What is the significance of calculating the angle and speed of a rock launched from a cliff catapult?

Calculating the angle and speed of a rock launched from a cliff catapult allows us to predict the trajectory of the projectile and determine where it will land. This information is important for safety and accuracy purposes.

3. What factors influence the angle and speed of a rock launched from a cliff catapult?

The angle and speed of a rock launched from a cliff catapult can be influenced by several factors such as the force used to launch the rock, the weight and size of the rock, and the angle at which it is launched. Wind resistance and air density can also affect the trajectory of the projectile.

4. Is there a specific formula for calculating the angle and speed of a rock launched from a cliff catapult?

Yes, there are specific equations for calculating the angle and speed of a rock launched from a cliff catapult. These equations are derived from the laws of motion and can be found in most physics textbooks or online resources.

5. Can the angle and speed of a rock launched from a cliff catapult be adjusted to change its trajectory?

Yes, by changing the angle and speed at which the rock is launched, its trajectory can be altered. For example, a higher launch angle will result in a shorter, higher arc while a lower launch angle will result in a longer, flatter trajectory.

Similar threads

  • Introductory Physics Homework Help
Replies
5
Views
3K
  • Introductory Physics Homework Help
Replies
12
Views
9K
  • Introductory Physics Homework Help
Replies
3
Views
14K
  • Introductory Physics Homework Help
Replies
3
Views
15K
  • Introductory Physics Homework Help
Replies
9
Views
2K
  • Introductory Physics Homework Help
Replies
2
Views
3K
  • Introductory Physics Homework Help
Replies
2
Views
6K
  • Introductory Physics Homework Help
Replies
4
Views
5K
  • Introductory Physics Homework Help
Replies
4
Views
6K
Replies
1
Views
937
Back
Top