Answer:
friction reduces the efficiency of machines, thus we must reduce the friction force that is acting upon it.
Answer:
The work done on the object by the force in the 5.60 s interval is 40.93 J.
Explanation:
Given that,
Force 
Mass of object = 2.00 kg
Initial position 
Final position 
Time = 4.00 sec
We need to calculate the work done on the object by the force in the 5.60 s interval.
Using formula of work done


Put the value into the formula




Hence, The work done on the object by the force in the 5.60 s interval is 40.93 J.
Answer:
The number of excess electrons on each sphere is 759
Explanation:
Given that,
distance , d = 20 cm
= 0.20 m
let the number of electrons is n
Electric force (F) = k × (n × e)² /d²
3.33 ×
= 9 ×
× (n × 1.602 ×
)² /0.2²
solving for n
n = 759