The ballerinas takes advantage of the moment of interia by not stretching her hands out etc. and by doing so decreasing the moment of interia and therefore a smaller torque is produced to rotate at a faster rate.
Answer:
10 m/s
Explanation:
Kinetic energy= 
mv² where m is mass and v is velocity.
We have to make v the subject so we should rearrange the equation
K=mv²
v²= 
(use algebra)
v²= 7/0.5×0.140
v²=100
v=√100
v=10 m/s
We can confirm this by using the kinetic energy formula.
K=×0.140×10²
K= 7 J
Hence it is proved that velocity is 10 m/s
B. As job efficiency increases, stress levels decline (THIS IS WRONG)I think its between A. As job efficiency decreases, stress levels increaseD. As stress levels increase, job efficiency increases
Answer:
15.7m/s
Explanation:
To solve this problem, we use the right motion equation.
Here, we have been given the height through which the ball drops;
Height of drop = 14.5m - 1.9m = 12.6m
The right motion equation is;
V² = U² + 2gh
V is the final velocity
U is the initial velocity = 0
g is the acceleration due to gravity = 9.8m/s²
h is the height
Now insert the parameters and solve;
V² = 0² + 2 x 9.8 x 12.6
V² = 246.96
V = √246.96 = 15.7m/s
