Answer: -31.36 m/s
Explanation:
This is a problem of motion in one direction (specifically vertical motion), and the equation that best fulfills this approach is:
(1)
Where:
is the final velocity of the supply bag
is the initial velocity of the supply bag (we know it is zero because we are told it was "dropped", this means it goes to ground in free fall)
is the acceleration due gravity (the negtive sign indicates the gravity is downwards, in the direction of the center of the Earth)
is the time
Knowing this, let's solve (1):
(2)
Finally:
Note the negative sign is because the direction of the bag is downwards as well.
Because of the law of inertia and it’s effect on the skater
Let the mass of the person be m. Total momentum is conserved (because the exterior forces on the system are balanced), especially the component in the vertical direction.
Given that,
Mass of gallon is M
Let man mass be m
Velocity of man is v
Let velocity if ballot be Vb
When the person begin to move we have
Conservation of momentum
mv + MVb=0
MVb=-mv
Vb= -(m/M) v
Given that the mass of man is less than mass of balloon. i.e. m<M
So, if m<M, then, m/M <1
Therefore, .
Vb= -(m/M) v
Vb< -v
This implies that the velocity of balloon is less than the velocity of man and if is also moving in opposite direction
So the man is moving upward, then the balloon is moving downward and it's velocity is less than the velocity of man,
The answer is C
Down with a speed less than v
