Answer:
26.8 seconds
Explanation:
To solve this problem we have to use 2 kinematics equations: *I can't use subscripts for some reason on here so I am going to use these variables:
v = final velocity
z = initial velocity
x = distance
t = time
a = acceleration


First let's find the final velocity the plane will have at the end of the runway using the first equation:


Now we can plug this into the second equation to find t:


Then using 3 significant figures we round to 26.8 seconds
"At the bottom, the car has X joules of mechanical energy" is the one among the following choices given in the question that <span>the law of conservation of energy predict about the car. The correct option among all the options that are given in the question is the second option or option "B". I hope the answer helped you.</span>
Answer:
The answer is 0.83 seconds.
Explanation:
The formula of free fall is following:

Where g=9.8 m/s^2 and t=2 seconds, the rock takes:

19.6 meters. This is the half distance of the cliff. The whole distance is 39.2 meters. So it takes:

2.83 second to fall down completely. The rock takes the second half of the cliff in 0.83 seconds
This is a non testable question because it cannot be answered by doing an experiment. But it could be modified for example Dogs are more obedient then cats.