Answer:
The rock will take about 4.5 seconds to reach the river
Step-by-step explanation:
* lets study the situation of the rock
- The rock is dropped means the initial velocity is zero
- The motion is free fall under earth gravity
- The rock dropped from a bridge 320 feet above the river
- The equation of the pathway is h = -16t² + 320
- When the rock reach to the ground the height will be zero
* Now lets substitute h by zero in the equation to find t
∵ h = -16t² + 320
∵ h = 0
∴ 0 = -16t² + 320 ⇒ add 16t² to both sides
∴ 16t² = 320 ⇒ divide both sides by 16
∴ t² = 320/16 = 20
∴ t² = 20 ⇒ take √ for both sides
∴ t = √20 = 2√5 ≅ 4.5 seconds
* The rock will take about 4.5 seconds to reach the river
Answer:
Option (3)
Step-by-step explanation:
If binomial (x - 6) and trinomial (-2x² + x + 9) are the factors of a polynomial then their multiplication will be equal to the polynomial.
(x - 6)(-2x² + x + 9) = x(-2x² + x + 9) - 6(-2x² + x + 9)
= -2x³ + x² + 9x + 12x² - 6x - 54
= -2x³ + 13x² + 3x - 54
Therefore, Option (3) will be the correct option.
Answer:
1.54 in²
Step-by-step explanation:
Given that,
→ Radius (r) = 0.7 in
Formula we use,
→ πr²
The area of the circle will be,
→ πr²
→ (22/7) × 0.7 × 0.7
→ (22/7) × 0.49
→ [ 1.54 in² ]
Hence, area of circle is 1.54 in².
Answer:
Step-by-step explanation:
a) One can get maximum score when all the 20 questions answered are correct.
Maximum score = 20*3 = 60 points
b) Minimum score = 20 * (-2) = -40 points
c) Points for correctly answered questions = 10*3 = 30
Incorrectly answered questions = 14 - 10 = 4
Points for incorrectly answered questions = 4 * (-2) = -8
Total score = 30 + (-8) = 22
d) Points for correctly answered questions =5*3 = 15
Points for incorrectly answered questions = 13 * (-2) = -26
Total score = 15 + (-26) = -11
