Answer <span>-7/24 - (-5/8) = 1/3</span>
Well when she hits the water h=0 so
2t^2-t-6=0 factor
2t^2-4t+3t-6=0
2t(t-2)+3(t-2)=0
(2t+3)(t-2)=0, since t>0
t=2 seconds...
However it should be noted that h(t)=-2t^2+t+6 implies that
v(t)=dh/dt=-4t+1 and
a(t)=dv/dt=-4
Since this is a free fall equation, this would suggest that the acceleration due to gravity is -4, whether that is supposed to be -4ft/s^2 or -4m/s^2, it certainly is not on this planet! :D If it is -4ft/s^2 it could be on the Moon or if it is -4m/s^2 it could be on Mars.
Answer: 13
Althoug each round trip takes 9 minutes and can carry 5 people on the boat, you can not just divide the 20 minutes time by 9 and multiply by 5 to find the number of people that are saved without getting wet.
First trip:
5 people take the boat to the island but only 4 can stay, because one has to return with the boat to the ship to rescue other 4 people.
So, when 9 minutes have passed, 4 people are safe on the island and the boat is again by the ship.
Second trip:
In the second trip, other 4 people are rescued,along with "sailor" who returned in the boat to rescue them.
When it has passed 18 minutes, the boat is next to the ship agin to carry other 4 people before the boat sinks.
This is the last trip before the boat sinks. So, the total number of passengers rescued is 4 + 4 + 5 = 13
