Answer:
Explanation:
The acceleration of an object is the rate of change of velocity of the object.
Mathematically, it is calculated as:
where
u is the initial velocity
v is the final velocity
t is the time taken for the velocity to change from u to v
Acceleration is a vector, so it is important to also take into account the direction of the velocity.
For the particle in this problem, we have:
u = +48 m/s is the initial velocity (positive direction)
v = -92 m/s is the final velocity (negative direction)
t = 4.5 s is the time interval
Therefore, the average acceleration is
Answer:
The equation for the object's displacement is
Explanation:
Given:
m = 16 lb
δ = 3 in
The stiffness is:
The angular speed is:
The damping force is:
Where
FD = 20 lb
u = 4 ft/s = 48 in/s
Replacing:
The critical damping is equal:
Like cc>c the system is undamped
The equilibrium expression is:
Answer:
0.79 s
Explanation:
We have to calculate the employee acceleration, in order to know the minimum time. According to Newton's second law:
The frictional force is maximum since the employee has to apply a maximum force to spend the minimum time. In y axis the employee's acceleration is zero, so the net force is zero. Recall that
Now, we find the acceleration:
Finally, using an uniformly accelerated motion formula, we can calculate the minimum time. The employee starts at rest, thus his initial speed is zero: