Projectile motion with mass height and range

  • Thread starter SPiazzo
  • Start date
  • #1
7
0
Hello all I have a question I was hoping someone could answer for my homework.
A 78.0-kg boulder is rolling horizontally at the top of a vertical cliff that is h1 = 16 m above the surface of a lake, as shown in the figure below. The top of the vertical face of a dam is located d = 110 m from the foot of the cliff, with the top of the dam level with the surface of the water in the lake. A level plain is h2 = 28 m below the top of the dam.
a) What must be the minimum speed of the rock just as it leaves the cliff so it will travel to the plain without striking the dam?
b) How far from the foot of the dam does the rock hit the plain?

from what I could find on Google about it, it seems to be a conservation of energy problem as that is the only way you can relate mass to anything. As all of the kinematic equations I have seen in my book and notes have no variable for mass. I am also fairly certain that the limited amount of information in the problem means that the mass is simply not there for no reason.
Any help you could give would be great! Thanks!!
 

Answers and Replies

  • #2
tiny-tim
Science Advisor
Homework Helper
25,832
251
Welcome to PF!

Hello SPiazzo! Welcome to PF! :smile:
from what I could find on Google about it, it seems to be a conservation of energy problem as that is the only way you can relate mass to anything.
No, just use the standard constant acceleration equations. :wink:
 
  • #3
34,484
10,613
Please post homework questions in our homework section - I moved your thread.

I agree with tiny-tim, just use the formulas for constant acceleration.
 

Related Threads on Projectile motion with mass height and range

Replies
1
Views
986
Replies
7
Views
985
  • Last Post
Replies
3
Views
899
  • Last Post
Replies
5
Views
41K
Replies
9
Views
14K
Replies
9
Views
4K
Replies
2
Views
6K
Replies
3
Views
10K
  • Last Post
Replies
10
Views
3K
Top