Answer:
Melissa = D
Victor = C
Step-by-step explanation:
5/13t= -9
Then t =( -9*13) / 5
T=-23.4
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
A and D... i think but i would rather go with A and C
Step-by-step explanation:
Let vertical height of ladder from ground be y and
horizontal distance of the base of the ladder from the wall be x respectively.
Length of the ladder = l (constant) = 10 ft
<u>Using Pythagoras theorem</u>:
Differentiate both sides w.r.t time
<u>We know that</u> (After 1 sec, y = 6 ft and x = 8 ft ; dy/dt = 2 ft/sec)
<u>( Ignore - ive sign)</u>
Therefore, bottom of the ladder is sliding away from the wall at a speed of 1.5 ft/sec one second after the ladder starts sliding.
