a) uniform velocity
b) zero or no acceleration
c) (see picture)
EXPLANATION:
(see picture)
Answer:
Normal force=mg
Explanation:
The reaction force of weight is the normal force.
in order to find the normal for we need to write all the forces and set it equal to the net force:
N-mg=ma (since it is a constant speed the a=0)
N=mg
A tool or machine's work efficiency is represented by the ratio of the amount of energy exerted and the amount of work done by the object. Thus, if you exert 1500 J work and the hammer does 825 J, the work efficiency is


Thus, the efficiency of the hammer is 55%.
Answer: 55%