A friend of yours who has not taken astronomy sees a meteor shower (she calls it a bunch of shooting stars). The next day she co
1 answer:
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Answer:
Part a)
Velocity of sled
velocity of first man who jump off
Part b)
Velocity of sled
Also the speed of second person is given as
Part c)
change in kinetic energy of sled + two people is given as
Explanation:
As we know that here we we consider both people + sled as a system then there is no external force on it
So here we can use momentum conservation
since both people + sled is at rest initially so initial total momentum is zero
now when first people will jump with relative velocity "s" then let say the sled + other people will move off with speed v
so by momentum conservation we have
so velocity of the sled + other person is
velocity of first man who jump off
Part b)
now when other man also jump off with same relative velocity
so let say the sled is now moving with speed vf
so by momentum conservation we have
Now we have
Also the speed of second person is given as
Part c)
change in kinetic energy of sled + two people is given as
here we know all values of speed as we found it in part a) and part b)
Answer:
<em>Option b is correct: 4.1 s</em>
Explanation:
<u>Vertical Launch</u>
An object launched thrown vertically upward where air resistance is negligible, reaches its maximum height in a time t, given by the equation:
Where vo is the initial speed and g is the acceleration of gravity g=9.8 .
Once the object reaches that point, it starts a free-fall motion, whose speed is (downward) given by:
The object considered in the question is thrown with vo=25 m/s. The time taken to reach the maximum height is given by [1]:
The object starts its falling motion and at some time, it has a speed of vf=15 m/s. Let's find the time by solving [2] for t:
The total time taken by the object to go up and down is
a. This option is incorrect because it's far away from the answer.
d. This option is incorrect because it's far away from the answer.
b. This option is correct because it's a good approximation to the calculated answer.
e. This option is incorrect because it's far away from the answer.
c. This option is incorrect because it's far away from the answer.