Answer:2.5 m/s
37.5KJ
Explanation:
Let
be the initial velocity of rail road car ,coupled cars & Final velocity of system respectively.

Conserving momentum



Therefore Final velocity of system is 2.5m/s
(b)Mechanical Energy lost =Initial Kinetic Energy -Final Kinetic Energy



Answer:
the person will be in the shore at 10.73 minutes after launch the shoe.
Explanation:
For this we will use the law of the lineal momentum.

Also,
L = MV
where M is de mass and V the velocity.
replacing,

wher Mi y Vi are the initial mass and velocity, Mfp y Vfp are the final mass and velocity of the person and Mfz y Vfz are the final mass and velocity of the shoe.
so, we will take the direction where be launched the shoe as negative. then:
(70)(0) = (70-0.175)(
) + (0.175)(-3.2m/s)
solving for
,
= 
= 0.008m/s
for know when the person will be in the shore we will use the rule of three as:
1 second -------------- 0.008m
t seconds-------------- 5.15m
solving for t,
t = 5.15m/0.008m
t = 643.75 seconds = 10.73 minutes
d.) a and b only
This is because sound needs a medium to travel. It can travel in a solid (the fastest) and air for example. Sound waves cannot propagate through a vacuum and since space is a vacuum the answer is a and b only.
Answer:
ssooeorkgogogoogkrorooror
Explanation: