Answer:
C po baka namn nakatulong
Answer:
Work done, W = 5534.53 J
Explanation:
It is given that,
Force acting on the piano, F = 6157 N
It is pushed up a distance of 2.41 m friction less plank.
Let W is the work done in sliding the piano up the plank at a slow constant rate. It is given by :

Since,
(in vertical direction)

W = 5534.53 J
So, the work done in sliding the piano up the plank is 5534.53 J. Hence, this is the required solution.
Sifting is the best method cuz all the dirt will be carried by wind.
The speed of the brick dropped by the builder as it hits the ground is 17.32m/s.
Given the data in the question;
Since the brick was initially at rest before it was dropped,
- Initial Velocity;

- Height from which it has dropped;

- Gravitational field strength;

Final speed of brick as it hits the ground; 
<h3>Velocity</h3>
velocity is simply the same as the speed at which a particle or object moves. It is the rate of change of position of an object or particle with respect to time. As expressed in the Third Equation of Motion:

Where v is final velocity, u is initial velocity, h is its height or distance from ground and g is gravitational field strength.
To determine the speed of the brick as it hits the ground, we substitute our giving values into the expression above.

Therefore, the speed of the brick dropped by the builder as it hits the ground is 17.32m/s.
Learn more about equations of motion: brainly.com/question/18486505