Answer:
5.714 hours / day
Explanation:
<u>Calculate the hours used in that week </u>
120000 / 3000 = 120 / 3 = 40 hours a week
<u>Calculate the amount it is used in one day</u>
40 / 7 = 5.71428571 hours or 5.714 hours/day
Answer:
ΔU = 2 mg h
Explanation:
In a spring mass system the potential energy is U = m g h
where h is measured from the equilibrium point of the spring
the potential energy at the highest point is
U₁ = m g h
the potential energy at the lowest point is
U₂ = m g (-h)
instead in this energy it is
ΔU = 2 mg h
In this two points the kinetic energy is zero, but there is elastic potential energy that has the same value in the two points, so its change is zero
Answer:
a)
, b) 
Explanation:
a) The equation for vertical velocity is obtained by deriving the function with respect to time:

The velocities at given instants are, respectivelly:


What is your question exactly? I'm confused?
Speed v = initial speed u + acceleration a x time t
v=u+at = 2 + 4*3 = 14 m/s