Projectile review

  • Thread starter kayjaydee
  • Start date
  • #1
5
0

Homework Statement



Block I of mass 4.0 kg is on a horizontal, frictionless tabletop and is placed against a spring of negligible mass and spring
constant 650 N/m. The other end of the spring is attached to a wall. The block is pushed toward the wall until the spring has been compressed a distance x, as shown above. The block is released and follows the trajectory shown, falling 0.80 m vertically and striking a target on the floor that is a horizontal distance of 1.2 m from the edge of the table. Air resistance is negligible.
a.Calculate the time elapsed from the instant block I leaves the table to the instant it strikes the floor.

b.Calculate the speed of the block as it leaves the table.

c.Calculate the distance the spring was compressed.


Homework Equations



d=vot+1/2at^2
v=vo+at
v^2=vo^2+2ad

The Attempt at a Solution



I really forgot how to do this. We are so far ahead of this unit, now, that I lost all my projectile motion mojo.
I'm guessing you solve for time using the spring constant and one of the above equations, but that's all that I know. I'm really rusty in the projectile area. :(
 

Answers and Replies

  • #2
390
1
Since the block leaves the table with no initial downward motion you can solve the equation
[tex] s = v_0t + \frac{1}{2}at^2 [/tex]
Where [itex] s [/itex] is the distance from the table top to the floor and [itex] a [/itex] is the acceleration due to gravity.
From this time you can use the same equation again using [itex] s [/itex] as the horizontal distance moved.
For the third part try the work energy theorem :)
 
  • #3
5
0
Okay! I think I understand now! thank you!
 
  • #4
390
1
No problem, good luck! :)
 

Related Threads on Projectile review

  • Last Post
Replies
10
Views
1K
  • Last Post
Replies
6
Views
1K
  • Last Post
Replies
1
Views
2K
Replies
6
Views
6K
Replies
7
Views
2K
  • Last Post
Replies
1
Views
3K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
1
Views
817
  • Last Post
Replies
2
Views
882
  • Last Post
Replies
6
Views
2K
Top