Answer:
option B
Explanation:
given,
height of building = 0.1 km
ball strikes horizontally to ground at = 65 m
speed at which the ball strike = ?
vertical velocity = 0 m/s
time at which the ball strike



t = 4.53 s
vertical velocity at the time 4.53 s = g × t = 9.8 × 4.53 = 44.39 m/s
horizontal velocity =
=14.35 m/s
speed of the ball =
= 46.65 m/s
hence, the speed of the ball just before it strike the ground = 47 m/s
The correct answer is option B
We can use the equation vf (the final velocity) =vi (the initial velocity) +at (aceleration times time)
We know the final velocity 100m/s, the initial velocity 0, and the acceleration (gravity) 9.8m/s^2. So, 100=0+9.8t. t=100/9.8
Answer:
0.000000083333 seconds = 83.333 nanoseconds
Explanation:
The speed of light is approximately 300.000.000 m/s, that means in one second, the light travels 300.000.000 meters.
We can solve that problem using rule of three:
If the light travels 300.000.000 meters in 1 second, to travel 25 meters how long it will take? (let's call the time we want by "T")
300.000.000 - 1
25 - T
300.000.000/25 = 1/T
T = 25/300.000.000
T = 0.000000083333 seconds = 83.333 nanoseconds
Answer: At that moment, all the baseball's kinetic energy has been converted to potential energy.
Explanation: I took the test