Answer:
a) 72.25sec
b) 6.25secs
c) after 10.5secs and 2 secs
Step-by-step explanation:
Given the height reached by the rocket expressed as;
s(t)= -4t^2 + 50t - 84
At maximum height, the velocity of the rocket is zero i.e ds/dt = 0
ds/dt = -8t + 50
0 = -8t + 50
8t = 50
t = 50/8
t = 6.25secs
Hence it will reach the maximum height after 6.25secs
To get the maximum height, you will substitute t - 6.25s into the given expression
s(t)= -4t^2 + 50t - 84
s(6.25) = -4(6.25)^2 + 50(6.25) - 84
s(6.25) = -156.25 + 312.5 - 84
s(6.25) = 72.25feet
Hence the maximum height reached by the rocket is 72.25feet
The rocket will reach the ground when s(t) = 0
Substitute into the expression
s(t)= -4t^2 + 50t - 84
0 = -4t^2 + 50t - 84
4t^2 - 50t + 84 = 0
2t^2 - 25t + 42 = 0
2t^2 - 4t - 21t + 42 = 0
2t(t-2)-21(t-2) = 0
(2t - 21) (t - 2) = 0
2t - 21 = 0 and t - 2 = 0
2t = 21 and t = 2
t = 10.5 and 2
Hence the time the rocket will reach the ground are after 10.5secs and 2 secs
The area of the circle, to two decimal places, is A = 3.14(1.8 m)^2
Then A = 10.17 m^2.
Answer:
True answer: -24
Step-by-step explanation:
<em><u>Showing the error</u></em>
-16-2(-2) – 12 First you need to multiply
8(-2) - 12 The error here is that the wrong numbers are multiplied together
-16-12 Add the negatives together
-28 Your answer (the incorrect one)
<em><u /></em>
<em><u>The correct way of solving it</u></em>
-16 -2(-2) - 12 Multiply into the parenthesis
-16 + 4 -12 Add the first two numbers
-12 - 12 Add the numbers together
-24 The answer
96 pints are bigger
Happy studying!
Answer:
The height of the toy is 9 feet after 1 second
Step-by-step explanation:
we have
where
h(t) is the toys height from the ground
t is the time in seconds
so
For t=1 sec
substitute the value of t in the quadratic equation and solve for h(t)
