1. pulling tug of war
2. monkey swinging from vine
3. arm wrestle
The EPA requires treated tap water<span> to have a detectable </span>level of chlorine<span> to help prevent contamination. The allowable </span>chlorine <span>in </span>drinking water<span> (up to 4 parts per million) pose “no known or expected health risk [including] an adequate margin of safety.”</span>
Answer:
Explanation:
Initial height from the ground = .41 m
Final height = 1m
Height by which Kelli was raised ( h )= .59 m
When she passes through the lowest point , she loses P E
= mgh
= 440 x .59
= 259.6 J
kinetic energy possessed by her
= 1/2 mv²
= .5 x (440/9.8) x 2²
= 89.8 J
Difference of energy is lost due to work by air friction
work done by friction = 89.8 - 259.6
= - 169.8 J
Answer:
Explanation:
How long does the football need to rise?
4.70/3 = 2.35 s
What height will the football reach?
h = ½(9.81)2.35² = 27.1 m
With what speed does the punter need to kick the football?
vy = g•t = 9.81(2.35) = 23.1 m/s
vx = d/t = 56.0/4.70 = 11.9 m/s
v = √(vx²+vy²) = 26.0 m/s
At what angle (θ), with the horizontal, does the punter need to kick the football?
θ = arctan(vy/vx) = 62.7°
