- #1
oneman49
- 3
- 0
Hi,
Im new to PF and Physics so pardon my likely extremely basic question (teaching myself physics).
1.) Question: (a) an empty sled is sliding on frictionless ice when susan drops vertically from a tree above onto the sled. When she lands, does the sled speed up, slow down, or keep the same speed? (b) Later, susan falls sideways off the sled. When she drops off, does the sled speed up, slow down, or keep the same speed?
2.) Relevant Equation(s)
Conservation of momentum?
m1v1 + m2v2 = m1v1' + m2v2'
3.) Attempts:
(a) this makes sense to me - I think. Initially the sled has some momentum but susan does not. When susan lands on the sled all she has is vertical velocity and not horizontal. Thus, the equation might look something like (assume 1 is the sled and 2 is susan):
m1v1 + 0 = v(m1+m2)
-when solving for v using some numbers the speed has decreased - I think that's right.
(b) honestly do not know where to start with this one - if someone could point me in the right direction in order to solve this I would greatly appreciate it. I know that susan will for a few seconds (or ms) have a horizontal velocity equal to what she previously had on the sled but I am stuck after that. If her momentum doesn't change then neither does the sleds?? So confused...
Im new to PF and Physics so pardon my likely extremely basic question (teaching myself physics).
1.) Question: (a) an empty sled is sliding on frictionless ice when susan drops vertically from a tree above onto the sled. When she lands, does the sled speed up, slow down, or keep the same speed? (b) Later, susan falls sideways off the sled. When she drops off, does the sled speed up, slow down, or keep the same speed?
2.) Relevant Equation(s)
Conservation of momentum?
m1v1 + m2v2 = m1v1' + m2v2'
3.) Attempts:
(a) this makes sense to me - I think. Initially the sled has some momentum but susan does not. When susan lands on the sled all she has is vertical velocity and not horizontal. Thus, the equation might look something like (assume 1 is the sled and 2 is susan):
m1v1 + 0 = v(m1+m2)
-when solving for v using some numbers the speed has decreased - I think that's right.
(b) honestly do not know where to start with this one - if someone could point me in the right direction in order to solve this I would greatly appreciate it. I know that susan will for a few seconds (or ms) have a horizontal velocity equal to what she previously had on the sled but I am stuck after that. If her momentum doesn't change then neither does the sleds?? So confused...