Answer:
The moment of inertia decreased by a factor of 4
Explanation:
Given;
initial angular velocity of the ice skater, ω₁ = 2.5 rev/s
final angular velocity of the ice skater, ω₂ = 10.0 rev/s
During this process we assume that angular momentum is conserved;
I₁ω₁ = I₂ω₂
Where;
I₁ is the initial moment of inertia
I₂ is the final moment of inertia
Therefore, the moment of inertia decreased by a factor of 4
X + y = 5
x = 5 - y
2x - y = 7
2(5-y) - y = 7
10 - 2y - y = 7
10 - 3y = 7
10 - 7 = 3y
3 = 3y
y = 1
x + y = 5
x + 1 = 5
x = 5 - 1
x = 4
Answer:
4948020
Explanation:
(6.9*10-6)(770*102)
<u>Multiply 6.9 by 10
.
</u>
(
69
−
6
)
(
770
⋅
102
)
<u>Subtract 6 from 69
.
</u>
63
(
770
⋅
102
)
<u>Multiply 770 by 102
.
</u>
63
⋅
78540
<u>Multiply 63 by 78540
.
</u>
4948020
Weight = mass * gravity
420 = mass * 9.8
mass of Betty = 42.857 kg
Difference in height = 1 - 0.45 = 0.55 meters
Total energy = Kinetic energy + potential energy
At the highest point, the kinetic energy is zero while the potential energy is maximum, therefore, we can get the total energy as follows:
Total energy = 0 + mgh
Total energy = 42.857*9.8*0.55 = 231 Joules
At the lowest point, the potential energy is zero while the kinetic energy is maximum. Therefore:
Total energy = 0.5 * m * (v)^2 + 0
231 = 0.5 * (42.857) * (velocity)^2
(velocity)^2 = 10.78
velocity = 3.28 meters/sec
