Answer:
The rise from A to B is 0.887
Solution:
As per the question:
The following reading of an inverted staff is given as:
A = 2.915
B = -2.028
Here, for inverted staff, the greater reading shows greater elevation and lesser reading shows lower elevation.
Thus
The rise from A to B is given as:
A - B = 2.915 - 2.028 = 0.887
Answer:
Kinetic energy cannot be negative
potential energy is a reference dependent quantity and it can be positive as well as negative both
Since potential energy is defined only for conservative force so it can not be found for friction force
Explanation:
Kinetic energy of an object is given by the formula

here we know that
m = mass of object that can not be negative
v = speed of the object and since its square is given here so it can not be negative
so Kinetic energy is always positive
potential energy is given as the energy due to the virtue of the position of object
so it is

so potential energy is a reference dependent quantity and it can be positive as well as negative both
Since potential energy is defined only for conservative force so it can not be found for friction force
Work done by force is given by formula

now here work done against friction is given so force of friction here is

It moved by three corridors with each measures

so total distance will be

now from above formula of work done we will say


so above is the work done to move three corridors