Sarah shoots a toy dart vertically downward at 11.7 m/s at Mark standing on the ground below. Calculate the dart's velocity after 0.8 seconds.
no
To calculate the dart's velocity after 0.8 seconds, we need to consider the acceleration due to gravity acting on the dart.
The acceleration due to gravity is approximately 9.8 m/s² and always acts downward. Since the dart is being shot vertically downward, its acceleration will be in the same direction.
Using the equation of motion: vf = vi + at,
Where:
vf = final velocity
vi = initial velocity
a = acceleration
t = time
Given:
vi = 11.7 m/s (since the dart is being shot downward, the initial velocity is negative)
a = 9.8 m/s² (acceleration due to gravity)
t = 0.8 s
Substituting these values into the equation, we have:
vf = 11.7 m/s + (-9.8 m/s²) * 0.8 s
vf = 11.7 m/s - 7.84 m/s
vf = 3.86 m/s
Therefore, the dart's velocity after 0.8 seconds is approximately 3.86 m/s in the downward direction.