Bullet into block of wood on table edge

AI Thread Summary
A 17 g bullet traveling at 475 m/s strikes a 0.7 kg block of wood balanced on a table edge 0.7 m high, and the task is to find the distance D where the block hits the floor. To solve this, the conservation of momentum should be applied to determine the initial velocity of the block after the bullet embeds itself. The vertical motion can then be analyzed to calculate the time it takes for the block to fall to the ground. Finally, the horizontal distance can be calculated using the time from the vertical motion. This approach effectively breaks the problem into manageable components for a solution.
KendrickLamar
Messages
26
Reaction score
0

Homework Statement


A 17 g bullet traveling 475 m/s strikes a 0.7 block of wood that is balanced on a table edge 0.7 m above ground. If the bullet buries itself in the block, find hte distance D at which the block hits the floor.

Diagram:
Y2uXO.gif



Homework Equations


Wnc = delta KE + delta PE?
Law of conservation?


The Attempt at a Solution



Just have no idea really how to attack this problem, but I am guessing it has to be broken into components somehow or something? just really confused on this one can someone get me started?
 
Physics news on Phys.org
Start by using conservation of Momentum.
 
KendrickLamar said:

Homework Statement


A 17 g bullet traveling 475 m/s strikes a 0.7 block of wood that is balanced on a table edge 0.7 m above ground. If the bullet buries itself in the block, find hte distance D at which the block hits the floor.

Diagram:
Y2uXO.gif



Homework Equations


Wnc = delta KE + delta PE?
Law of conservation?


The Attempt at a Solution



Just have no idea really how to attack this problem, but I am guessing it has to be broken into components somehow or something? just really confused on this one can someone get me started?

In problems like these you use the vertical component of the motion to work out how long [in time] it takes fro the block to reach the ground. You then use the horizontal component to find how far from the edge of the table it lands.
As mentioned in previous post, use conservation of momentum To find initial velocity of block.
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top