Answer:
Work done to pull the piano upwards is 401250 J
Explanation:
Work is done against the gravity to pull the piano upwards
So here we can say that work done is

here we know that

also we know that
H = 75 m
now we have


Answer:
Explanation:
You can approach an expression for the instantaneous velocity at any point on the path by taking the limit as the time interval gets smaller and smaller. Such a limiting process is called a derivative and the instantaneous velocity can be defined as.#3
For the special case of straight line motion in the x direction, the average velocity takes the form: If the beginning and ending velocities for this motion are known, and the acceleration is constant, the average velocity can also be expressed as For this special case, these expressions give the same result. Example for non-constant acceleration#1
The correct answer is B because isotopes have different numbers of neutrons, and neutrons are located in the nucleus
Hope this helps
I have all the answers here so take this