Answer:
3. none of these
Explanation:
The rotational kinetic energy of an object is given by:
where
I is the moment of inertia
is the angular speed
In this problem, we have two objects rotating, so the total rotational kinetic energy will be the sum of the rotational energies of each object.
For disk 1:
For disk 2:
so the total energy is
So, none of the options is correct.
The one that is loaded worst. The overall weight is not important; tongue weight is a matter of loading. Our 12,000 lb snow cat trailer, which has stops to position the cat properly, has under 100 lbs tongue weight. Excessive tongue weight is a Bad Thing because it reduces weight on the towing vehicle's front wheels, leading to instability.
From the conservation of linear momentum of closed system,
Initial momentum = final momentum
Mass of the student, M = 59 kg
Mass of the laser boat, m = 42 kg
Initial speed of student + laser boat, u =0
Final speed of laser boat, v = 1.5 m/s
Final speed of the student = V
(M+m) u =M V +m v
0 = (59 kg) V + (42 kg) (1.5m/s)
V = - 1.06 m/s
Thus, the speed of the student is 1.06 m/s in the opposite direction of the motion of boat.
Answer:
h=20.66m
Explanation:
First we need the speed when the cord starts stretching:
This will be our initial speed for a balance of energy.
By conservation of energy:
Where
is your height at its maximum elongation
is the height of the bridge
is the length of the unstretched bungee cord
Solving for h:
and 
Since 99m is higher than the initial height of 79m, we discard that value.
So, the final height above water is 20.66m
