Junior rides his trucycle off a level porch. If he left the porch at a speed of 4 m/s and landed a horizontal distance of 2.5m from the base, then what is the height of the porch?

the height of the porch is H=1.91 m

Step-by-step explanation:

neglecting friction and assuming that the porch is horizontal, then the horizontal speed is v₀= 4 m/s and it does not change , thus he hits the base at

t= L/v₀ , L= horizontal distance

then for vertical motion , since the vertical velocity vy is 0 , the initial height is H ( the height of the porche)  and the final height hf is 0 , we have

hf = H + vy*t - 1/2*g*t²

0 = H + 0 -1/2*g*t²

H = 1/2*g*t² = 1/2*g*(L/v₀)²

replacing values with g= gravity = 9.8 m/s²

H = 1/2*g*(L/v₀)² = 1/2*9.8 m/s² *( 2.5 m/ 4 m/s)² = 1.91 m

therefore the height of the porch is H=1.91 m

b

step-by-step explanation:

given

- 2 (3x + 12y - 5 - 17x - 16y + 4 )

simplify the parenthesis by collecting like terms

= - 2 (- 14x - 4y - 1) ← distribute the parenthesis by - 2

= 28x + 8y + 2 → b

15

step-by-step explanation:

we are given the following expression and we are to solve it and find the product:

-13 × (-5)

solving the given expression in the standard order of solving a mathematical expression, beginning with the opening of brackets and then multiplying the terms and changing their signs.

-3 × -5 = 15 (answer is positive because when negative is multiplied with negative, it gives a positive answer)