If we assume time starts counting when we release the weight from its fully-extended downward position, then the position at 1.15 seconds can be found from ...

h(t) = -7cos(2πt/4)

h(1.15) = -7cos(π·1.15/2) = -7(-0.233445) ≈ 1.63412 . . . cm

That is, 1.15 seconds after the weight is released from below the resting position, it will be 1.63 cm above the resting position.

If it is released from above the resting position, it will be 1.63 cm below the resting position at t=1.15 seconds.

6 0

3 years ago

Find the coefficient of correlation between and X and Y if covariance between X and Y is 15 and the variance of X and Y are resp

IRINA_888 [86]

Answer:

0.95

Step-by-step explanation:

$Correlation \ coefficient \ (r) = \dfrac{covaraince \ between \ X \ and \ Y }{SD_X \times SD_Y }$

$Correlation \ coefficient \ (r) = \dfrac{15 }{10^{1/2} \times 25^{1/2} }$

$Correlation \ coefficient \ (r) = \dfrac{15 }{3.162 \times 5 }$

$Correlation \ coefficient \ (r) = \dfrac{15 }{15.81 }$

$Correlation \ coefficient \ (r) \simeq 0.95$

5 0

2 years ago