SOLUTION: A flare is shot upwards from the deck of a ship. The initial upward velocity of the flare is 30m/s and the deck is 10m above the surface of the ocean. The height of the flare in me

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Question 355293: A flare is shot upwards from the deck of a ship. The initial upward velocity of the flare is 30m/s and the deck is 10m above the surface of the ocean. The height of the flare in metres is given by h=-5t^2 +30t+10, where t is in seconds.
Question: Determine the instantaneous velocity of the flare at t=3seconds, by using the slopes of secants (3marks:1mark for table, 2marks for slopes)
Can one of the tutors help me with the table, I cant seem to find a constant velocity.
Thank You!

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
A flare is shot upwards from the deck of a ship. The initial upward velocity of the flare is 30m/s and the deck is 10m above the surface of the ocean. The height of the flare in metres is given by h=-5t^2 +30t+10, where t is in seconds.
Question: Determine the instantaneous velocity of the flare at t=3seconds, by using the slopes of secants (3marks:1mark for table, 2marks for slopes)
Can one of the tutors help me with the table, I cant seem to find a constant velocity.
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There is no constant velocity, it changes from launch until impact.
The initial speed is 30 m/sec. At time t, it's 30 - 5t m/sec
At t = 3 seconds, it's 15 m/sec (+, still going up).
I don't know what the "slopes of secants" means.
To make a table, sub the times for t in 30 - 5t.