Use the equation for power to solve the following problems.

1. While rowing across the lake during a race, John does 3,960 J of work on the oars in 60.0s. What is his power output in watts?

2. Anna walks up the stairs on her way to class. She weighs 565N, and the stairs go up 3.25 m vertically.

a. If Anna climbs the stairs in 12.6 S, what is her power output?

b. What is her power output if she climbs the stairs in 10.5 s?

The equation for power is P = W/t, where P is power in watts, W is work in joules, and t is time in seconds. Plugging in the values given in the problem, we get:

P = W/t = 3,960 J / 60.0 s = 66.0 W

Therefore, John's power output is 66.0 watts.

The equation for power is P = W/t, where P is power in watts, W is work in joules, and t is time in seconds. To solve for power, we need to find the work done and the time it takes to do that work.

a. The work Anna does when climbing the stairs is equal to the force she exerts (her weight) times the distance she travels vertically. Using the equation W = Fd, where W is work, F is force, and d is distance, we get:

W = Fd = (565 N)(3.25 m) = 1836.25 J

The time it takes Anna to climb the stairs is given as 12.6 s. Plugging in the values, we get:

P = W/t = 1836.25 J / 12.6 s = 145.48 W

Therefore, Anna's power output when climbing the stairs in 12.6 s is 145.48 watts.

b. If Anna climbs the stairs in 10.5 s, the time is different but the work done is the same, so we can use the same value for W:

W = 1836.25 J

Plugging in the new time, we get:

P = W/t = 1836.25 J / 10.5 s = 174.88 W

Therefore, Anna's power output when climbing the stairs in 10.5 s is 174.88 watts.

The diagram below shows the phase of the moon as observed every seven days for a month.
Which moon phase would have been observed on Day 7?



A. First Quarter Moon
B. Waxing Gibbous
C. Third Quarter Moon
D. Waning Gibbous

100 PTS AND BRAINLIEST!!! GIVE DECENT ANSWERS!! Match the items on the left with the correct definition on the right. (also i have this asked already but it was an incorrect answer so if you want brainliest, go answer that one)

Match the term to its description.
Elliptical galaxy, Galaxy, Lens galaxy, Spiral galaxy
A) Is a collection of several billion stars and interstellar matter isolated in space
B) Has a large flattened core
C) Has a central core from which curved arms spiral outward
D) Forms a perfect sphere or an ellipse and is flattened to some degree
HELP ASAP WILL MARK BRAINLIEST!!!!!!!!!!!!!!

72 pts!!! Indicate on the wave graph the location of the following:

ASAP please
A student is playing with marbles. He rolls a purple marble, which strikes a green marble that is at rest. After the collision, the green marble rolls away from the student. The purple marble rolls back toward him.

Why does the purple marble roll back toward the student? Explain your response in terms of Newton’s third law.

100 POINTS!!! Match the items on the left with the correct definition on the right.