Answer:
The correct option is that (She decreases her moment of inertia, thereby increasing her angular speed.)
Explanation:
When an object is in circular motion, the vector that describes it is known as angular momentum. Angular momentum is conserved or constant when an object is spinning in a closed system and no external torques are applied to it. An example of conservation of angular momentum is seen when a woman is sitting on a spinning piano stool with her arms extended. Her angular momentum is conserved because the net torque on her is negligibly small as the friction is exerted very close to the pivot point.
When she folds her arms,her rate of spin increases greatly decreasing her moment of inertia. The work she does to pull in her arms results in an increase in rotational kinetic energy( that is, increase in her angular speed). I hope this helps, thanks!
Answer:
30 T
Explanation:
The magnetic field due to first wire at point A is 
Magnetic field due to second wire at point A is 
As the current flows in opposite direction in both the wire so net magnetic magnetic field at point A is 
So net magnetic field 
as 
is given as 10 T in question
7000w + 1637kw =8637kw+25.0m=loud sound
Answer:
The frictional force acting on the bear during the slide is 207.5 N
Explanation:
Given;
mass of beam, m = 25-kg
vertical height, h = 12 m
speed of fall, v = 6 m/s
Change in potential energy of the beam:
ΔP.E = -mgh = - 25 x 9.8 x 12 = -2940 J
Change in kinetic energy of the beam:
Δ K.E = ¹/₂mv² = ¹/₂ x 25 x (6)² = 450 J
Change in thermal energy of the system due to friction:
ΔE = - (ΔP.E + Δ K.E)
ΔE = - (-2940 J + 450 J)
ΔE = 2940 J - 450 J = 2490 J
Frictional force (in N) acting on the bear during the slide:
F x d = Fk x h = ΔE
Where;
Fk is the frictional force
Fk = ΔE/h
Fk = 2490J / 12m
Fk = 207.5 N
Therefore, the frictional force acting on the bear during the slide is 207.5 N
Hello! 10^3 is 1,000. There are 3 zeros behind the one, which makes one thousand. 1,000 * 5 is 5,000. 5 * 10^3 is 5,000 in standard form.
