Answer:
The weighted average is of 69.94.
Step-by-step explanation:
Weighted average:
The weighed average is found multiplying each grade by its respective weight.
The grades, and weights are:
67 on the lab, with a weight of 23% = 0.23
69 on the first major test, with a weight is 21.5% = 0.215
85 on the second major test, with a weight is 21.5% = 0.215.
63 on the final exam, with a weight of 34% = 0.34.
Weighted average:
The weighted average is of 69.94.
By the quadratic formula,
Then
Multiply numerator and denominator by the denominator's conjugate:
Answer:
Step-by-step explanation:
Power is defined by work over time. In physics, work can be defined as the energy transferred over from an applied force over some distance. As a formula:
, where F = force applied and d = distance that force is applied over.
*It is worth noting that F must be parallel to the distance travelled. If it is perpendicular, no work is done, and if it is at an angle, find the parallel component and use that for F.
In this case, the force applied must counter the force of gravity on Martha, which is given by , where m = Martha's mass and g = gravitational constant 9.8 m/s/s. Therefore,
. Since she raises her body 4.0 meters, the work done must be
.
Since power is equal to work over time and t = 2.3 seconds, we have:
(to two significant figures)