Answer:
When her hands extends, her momen of inertia is 
.
Explanation:
Given that,
Initial angular speed, 
Initial moment of inertia, 
Final angular speed, 
Initially, a skater rotates with her arms crossed and finally she extends her arms. The momentum remains conserved. Using the conservation of momentum as :
is final moment of inertia
So, when her hands extends, her momen of inertia is . Hence, this is the required solution.
Answer:
A) 3.13 m/s
B) 5.34 N
C) W = 26.9 J
Explanation:
We are told that the position as a function of time is given by;
x(t) = αt² + βt³
Where;
α = 0.210 m/s² and β = 2.04×10^(−2) m/s³ = 0.0204 m/s³
Thus;
x(t) = 0.21t² + 0.0204t³
A) Velocity is gotten from the derivative of the displacement.
Thus;
v(t) = x'(t) = 2(0.21t) + 3(0.0204t²)
v(t) = 0.42t + 0.0612t²
v(4.5) = 0.42(4.5) + 0.0612(4.5)²
v(4.5) = 3.1293 m/s ≈ 3.13 m/s
B) acceleration is gotten from the derivative of the velocity
a(t) = v'(t) = 0.42 + 2(0.0612t)
a(4.5) = 0.42 + 2(0.0612 × 4.5)
a(4.5) = 0.9708 m/s²
Force = ma = 5.5 × 0.9708
F = 5.3394 N ≈ 5.34 N
C) Since no friction, work done is kinetic energy.
Thus;
W = ½mv²
W = ½ × 5.5 × 3.1293²
W = 26.9 J
Answer:
The planes’ acceleration from A to B is 500m/s^2
Explanation:
Given that the initial velocity u is 8000m/s
and also given the final velocity v=10,000 m/s
the time taken to move from A to B = 40 second
The acceleration is defined as the rate of change of velocity with time
we know that the expression for acceleration is given as
a=(v-u)/t
substituting our given data into the expression for a we have
a=(10000-8000)/40
a=2000/40
a=500m/s^2
The planes’ acceleration from A to B is 500m/s^2
Answer:
Radiation
Explanation:
The fire from the burning house is not directly touching the house. Also not convection because there is not water involved
AnswerA tell me what u got sorry if its worng
Explanation:
