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.
Answer:
the answer is tropical rainfores
Efficiency is completing a task as fast a possible the the least amount of effort.
Answer:
x = 0.396 m
Explanation:
The best way to solve this problem is to divide it into two parts: one for the clash of the putty with the block and another when the system (putty + block) compresses it is spring
Data the putty has a mass m1 and velocity vo1, the block has a mass m2
. t's start using the moment to find the system speed.
Let's form a system consisting of putty and block; For this system the forces during the crash are internal and the moment is preserved. Let's write the moment before the crash
p₀ = m1 v₀₁
Moment after shock
= (m1 + m2) 
p₀ =
m1 v₀₁ = (m1 + m2) 
= v₀₁ m1 / (m1 + m2)
= 4.4 600 / (600 + 500)
= 2.4 m / s
With this speed the putty + block system compresses the spring, let's use energy conservation for this second part, write the mechanical energy before and after compressing the spring
Before compressing the spring
Em₀ = K = ½ (m1 + m2)
²
After compressing the spring
= Ke = ½ k x²
As there is no rubbing the energy is conserved
Em₀ = 
½ (m1 + m2)
² = = ½ k x²
x =
√ (k / (m1 + m2))
x = 2.4 √ (11/3000)
x = 0.396 m