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
Answer:
a) (2+8)+9
b) (3+7)+5+4
c) (4+16)+2
d) (31+9)+4
Step-by-step explanation:
a) 2+9+8
2 and 8 add up to 10, so we regroup them in parentheses
(2+8)+9
b) 3 + 5 + 4 + 7
3 and 7 add up to 10, so we regroup them in parentheses
(3+7)+5+4
c) 4 + 2 + 16
4 and 16 add up to 20 which is a multiple of 10, so we regroup them in parentheses
(4+16)+2
d) 31 + 4 + 9
31 and 9 add up to 40 which is a multiple of 10, so we regroup them in parentheses
(31+9)+4
Let’s assume that Laura has x$
Jose = 8+ x
Keith= 3x
So the total is equal to
118= x + 8 +x + 3x
118= 5x + 8
Subtract 8 from both sides
110= 5x
Divide 5 by both sides
22$= x which is what Laura has
Jose will have :8+22= 30$
Keith will have :3*22=66$
