The numerical value of the variance a. is negative if the mean is negative. b. is always larger than the numerical value of the
standard deviation. c. is always smaller than the numerical value of the standard deviation. d. can be larger or smaller than the numerical value of the standard deviation.
Variance is the sum of squares of all items x from mean. i.e
Variance =
Being the sum of squares variance can never be negative irrespective of mean being negative.
Std deviation is the square root of variances. This will thus be less than variance if variance >1 other wise std deviation will be bigger than variance.
- If the contact time between bat and ball is 3.00 10-3 s, calculate the average force between the ball and bat during contact. ... now that we have dp we divide it by 3 x 10^-3 s. ... therefore the average force ( or impulse) between the ball and the bat during contact is 12000 N.
