A football is kicked from a tee at 12 m/s at 72° above the horizontal. What is the maximum height of the football
1 answer:
The maximum height is reached when the vertical component of the velocity is zero.
vertical direction:
acceleration: a = -g = -9.81m/s²
velocity: v = -g*t + v₀
position: y = -0.5*g*t² + v₀*t + y₀
For v= 0:
0 = -g*t + v₀ => t = v₀/g
Insert into position equation gives:
y(max) = (-0.5*v₀²/g) + (v₀²/g) + y₀ = (0.5*v₀²/g) + y₀
vertical direction:
acceleration: a = -g = -9.81m/s²
velocity: v = -g*t + v₀
position: y = -0.5*g*t² + v₀*t + y₀
For v= 0:
0 = -g*t + v₀ => t = v₀/g
Insert into position equation gives:
y(max) = (-0.5*v₀²/g) + (v₀²/g) + y₀ = (0.5*v₀²/g) + y₀
You might be interested in
Answer:
1.117935:1
Explanation:
Since the wires are of the same material, they will have the same resistivity .
The cross-sectional area of the of a wire is given by;
where d is the diameter of the wire.
Also, the relationship between resistance R, cross-sectional area A and length l of a wire is given as follows;
Since the resistivity same for both wires, say wire 1 and wire 2, we can wreite the following;
Hence from eqaution (3), the ration of wire 1 to 2 is expressed as;
Given;
We then use equation (1) to fine the ratio of the area to
bearing in mind that
This ratio gives 0.8281. Substituting this into equation (5), we get the following;