Answer:
Value of magnitude of acceleration will be
Explanation:
It is given that when a stone is dropped it takes 2.2 sec to reach the ground
(a) As the stone is dropped from the top of building
So its initial velocity will be 0 m /sec
(b) As the stone is free falling and there is no external force applied on it so its acceleration will be equal to acceleration due to gravity
So value of magnitude of acceleration will be equal to
Explanation:
V=40m/s
Vy=V.sina=40.sin20=40 . 0.342=13.68m/s
Vx=V.cosa=40.cos20=40 . 0.766=30.64m/s
Projectile travels during 5 seconds and the ramge becomes:
x=V.t=30.64 . 5=153.2m
(a) 1200 rad/s
The angular acceleration of the rotor is given by:
where we have
is the angular acceleration (negative since the rotor is slowing down)
is the final angular speed
is the initial angular speed
t = 10.0 s is the time interval
Solving for , we find the final angular speed after 10.0 s:
(b) 25 s
We can calculate the time needed for the rotor to come to rest, by using again the same formula:
If we re-arrange it for t, we get:
where here we have
is the initial angular speed
is the final angular speed
is the angular acceleration
Solving the equation,