Answer:
Balanced force
Explanation:
Balanced Forces, When forces are in balance, acceleration is zero. Velocity is constant and there is no net or unbalanced force. ... Although friction is acting on the person, there is no change in velocity and friction is not a net force in this case. Friction is only a net force if it changes the velocity of a mass.
Answer:


Explanation:
In order to calculate the equivalent spring constant we need to use the next formula:

Replacing the data provided:


Finally, to calculate the frequency of oscillation we use this:

Replacing m and k:

In a block and tackle, some friction in the pulleys will reduce the mechanical advantage of the machine. To include friction in a calculation of the mechanical advantage of a block and tackle, divide the weight of the object being lifted by the weight necessary to lift it.
Hope this helps
Eugene Cernan was not the last, but he was the most recent.
Answer:
a) -1.25 rev/s² and 23.3 rev
b) 2.67s
Explanation:
a) ω
= (500 rev/min)(1min/ 60s) => 8.333 rev/s
ω
= (200 rev/min)(1min/ 60s) => 3.333rev/s
time 't'= 4 s
angular acceleration 'α
'=?
constant angular acceleration equation is given by,
ω
= ω
+ α
t
α
= (ω
- ω
)/t => (3.333-8.333)/4
α
= -1.25 rev/s²
θ-θ
= ω
t + 1/2α
t²
=(8.333)(4) + 1/2 (-1.25)(4)²
=23.3 rev
b) ω
=0 (comes to rest)
ω
= 3.333 rev/s
α
= -1.25 rev/s²
ω
= ω
+ α
t
t= (ω
- ω
)/α
=> (0- 3.333)/-1.25
t= 2.67s