Answer
10
Explanation:
goes up by 10 each time 10 to 20 to 30
K.E = 1/2*m*v^2 = 1/2(500)(3)^2 = 2250 J
m*g*h = 500(9.8)(30) = 147000 J
2250 + 147000 = 149250
Answer:
Time required by boat 1 for the round trip is less than that of boat 2.
Hence, boat 1 wins.
Explanation:
Case 1: Boat 1
Speed of boat = 
time = 
While going to another end
time = 
time = 
time = 1 hour
While going back,
time = 
time = 
time = 1 hour
Total time taken by boat 1 is,
Total time by boat 1 = 1 hour + 1 hour = 2 hour
Total time by boat 1 = 2 hour
Total time taken by boat 1 for the round trip is 2 hour.
Case 2: Boat 2
Speed of boat = 
time = 
While going to another end
time = 
time = 
time = 2 hour
While going back,
time = 
time = 
time = 0.66 hour
Total time taken by boat 2 is,
Total time by boat 1 = 2 hour + 0.66 hour
Total time by boat 1 = 2.66 hour
Total time taken by boat 2 for the round trip is 2.66 hour.
Time required by boat 1 for the round trip is less than that of boat 2.
Hence, boat 1 wins.
When the parachute deploys it increases the persons air resistance to (temporaily) greater than the force of weight. This causes them to decellerate. As they decellerate resistance decreases again until once again it balances out. Terminal velocity is reduced to a safe level, and landing without injury is possible.