It doesn't because when u threw it the first time, u notice that the ball eventually came to a stop because of the force that was acting upon it. Although when u throw it harder it will start out faster than the first time u threw it because u put more kinetic energy onto the ball. But the same thing happens with this ball that happened to the second ball, they both have a type of force acting upon them.
Answer:
a
The hiker (you ) is 200 m below his/her(your) starting point
b
The resultant displacement in the north east direction is

The resultant displacement in vertical direction (i.e the altitude change )

Explanation:
From the question we are told that
The displacement in the morning is 
The displacement in the afternoon is 
Generally the direction west is negative , the direction east is positive
the direction south is negative , the direction north is positive
resultant displacement is mathematically evaluated as



From the above calculation we see that at the end of the hiking the hiker (you) is 200 m below his/her(your) initial position
Generally from Pythagoras theorem , the resultant displacement in the north east direction is

=> 
Generally from Pythagoras theorem , the resultant displacement in vertical direction (i.e the altitude change )

=> 
Answer:
t = 0.28 seconds
Explanation:
Given that,
Force acting on a firework, F = 700 N
The momentum of the firework, p =200 kg-m/s
We need to find the time before it explodes. Ket the time be t. We know that, the rate of change of momentum is equal to external frce. So,

So, the required time is equal to 0.28 seconds.