a. When the ball thrown vertically up ward to reach its maximum height at velocity = 0 then complete its motion vertically down ward to strike the ground its displacement = zero

∴ s(t) = 0 ⇒ $80t-16t^{2}=0$

∴ $16t(5 - t) = 0$

5 - t = 0⇒ ∴ t = 5 seconds

b. To tind the time that the ball will be over 96 ft over the ground substitute in $s(t)=80t-16t^{2}$

$96=80t-16t^{2}$

$16t^{2}-80t+96=0$

$16(t^{2}-5t+6)=0$

$16(t-3)(t-2)=0$

t = 3 sec. and t = 2 sec.

The ball will be at height 96 ft at time 2 sec. and 3 sec.

So the ball will be at height over than 96 = 3 - 2 = 1 sec.

8 0

3 years ago

When 40% of a number is added to the number, the result is 504. Find the number

mestny [16]

Answer:

302.4

Step-by-step explanation:

40% of 504 =201.6

504-201.6=302.4

6 0

4 years ago

What single decimal multiplier would you use to decrease by 7% followed by a 20% decrease?

Nadusha1986 [10]

Answer:

13 percent

Step-by-step explanation:

6 0

3 years ago