Answer:
The angular acceleration α = 14.7 rad/s²
Explanation:
The torque on the rod τ = Iα where I = moment of inertia of rod = mL²/12 where m =mass of rod and L = length of rod = 4.00 m. α = angular acceleration of rod
Also, τ = Wr where W = weight of rod = mg and r = center of mass of rod = L/2.
So Iα = Wr
Substituting the value of the variables, we have
mL²α/12 = mgL/2
Simplifying by dividing through by mL, we have
mL²α/12mL = mgL/2mL
Lα/12 = g/2
multiplying both sides by 12, we have
Lα/12 × 12 = g/2 × 12
αL = 6g
α = 6g/L
α = 6 × 9.8 m/s² ÷ 4.00 m
α = 58.8 m/s² ÷ 4.00 m
α = 14.7 rad/s²
So, the angular acceleration α = 14.7 rad/s²
Answer:
Explanation:
You are looking for the resistance to start with
W = E * E/R
75 = 240 * 240 / R
75 * R = 240 * 240
R = 240 * 240 / 75
R = 57600 / 75
R = 768
Now let's see what happens when you try putting this into 110
W = E^2 / R
W = 120^2 / 768
W = 18.75
So the wattage is rated at 75. 18.75 is a far cry from that. I think they intend you to set up a ratio of
18.75 / 75 = 0.25
This is the long sure way of solving it. The quick way is to realize that the voltage is the only thing that is going to change. 120 * 120 / (240 * 240) = 1/2*1/2 = 1/4 = 0.25
Power = 1800W (or 1.8KW by dividing by 1000)
Time = 3 hours
Power = energy/ time
1.8KW = energy/ 3
x3
5.4Kw/h= energy
(5.4KJ or 5400J used)
$0.15 Kw/h
$0.15 X 5.4 = 0.81
Thus, cost $0.81
Hope this helps!
A). The apple has thermal energy, because its temperature is higher
than absolute zero.
It also has chemical energy, because if I eat it, I get a burst of energy
and I become ambitious for a while.
It also has gravitational potential energy, because if I drop it on my foot,
it could bruise one of my piggies.
b). I could increase its potential energy by lifting it higher, like over my head.
c). As long as I'm just holding the apple, it doesn't have any kinetic energy.
I could give it some kinetic energy by throwing it.
Or I could just drop it, and let gravity give it kinetic energy.
Answer:
The third drop is 0.26m
Explanation:
The drop 1 impacts at time T is given by:
T=sqrt(2h/g)
T= sqrt[(2×2.4)/9.8]
T= sqrt(4.8/9.8)
T= sqrt(0.4898)
T= 0.70seconds
4th drops starts at dT=0.70/3= 0.23seconds
The interval between the drops is 0.23seconds
Third drop will fall at t= 0.23
h=1/2gt^2
h= 1/2×9.81×(0.23)^2
h= 0.26m