I hope this helps you understand the steps to get your answer...
The equation is derived from the conservation of energy, specifically from potential energy stored at a given height in a gravitational field.
When potential energy is completely converted to kinetic energy you have:
(mv^2)/2=mgh divide both sides by the mass m
v^2/2=gh multiply both sides by 2
v^2=2gh take the square root of both sides
v=√(2gh) and working with imperial units for acceleration due to gravity, g=-32ft/s^2
v=√(-64h) but the change of h as it falls is negative h so
v=-√(64h) so if an object falls from a height of 88ft we have:
v=-√(64*84)
v=-√5376
v≈-73.32 ft/sec (to the nearest hundredth of a foot per second)
Note that this is the velocity, it is negative 73.32 ft/sec.
The question inadvertently asked for velocity and provided answers for SPEED. Velocity is a vector and has both magnitude and direction, whereas speed just has magnitude.
So its final speed is 73.32 ft/sec
So if they actually wanted velocity none of their answers is correct :P
1. 10 5/18 - 8 5/6
<span>C. 1 4/9
2.
1 2/5 ÷ 2 1/3
C. 3/5
</span>
The answer is $1.36 because you have to add $3.40+3.40 because he buys two airplanes. Afterwards you multiply times .20 and get 1.36 because you always have to move 20% two places to the left