how do you calculate if a block of wood dropped form a tall building has attained a velocity of of 78.4 m/s, how long has it been falling?
I don't understand the question.
if gravity is rounded to 10 and 78.4 is rounded to 78:
-then, time= velocity/gravity
time=78/10
time=7.8
or...
time=78.4/9.8
time= 8
To calculate the time it takes for the block of wood to reach a velocity of 78.4 m/s while falling, you can use the equation of motion that relates velocity to time:
v = u + at
Where:
- v is the final velocity (78.4 m/s)
- u is the initial velocity (0 m/s as the object starts from rest)
- a is the acceleration due to gravity (-9.8 m/s², assuming downward direction)
Rearranging the equation, we get:
t = (v - u) / a
Substituting the known values:
t = (78.4 m/s - 0 m/s) / -9.8 m/s²
Calculating this, we find that the time taken for the block of wood to reach a velocity of 78.4 m/s is approximately 8 seconds.
Therefore, it has been falling for 8 seconds.