The first thing you should know is that the work is defined as:
W = F * d
Where
F = force
d = displacement
We have then
(a) the block
F = (0.2) * (100) = 20
d = 100
W = (20) * (100) = 2000 ft.lbf
(b) the man as the system.
F = (0.2) * (100 + 180) = 56
d = 100
W = (56) * (100) = 5600 ft.lbf
answer:
(a) 2000 ft.lbf
(b) 5600 ft.lbf
A
because waves need air or something else to travel through
Multiply the masses by the respective distances:
(12 kg) (2 m) = 24 J
(25 kg) (1 m) = 25 J
so the heavier bag takes more work to lift, and (b) is the answer.
(d) is technically correct if the sacks are carrying different contents whose masses are not equal, but since we don't know what's inside each sack, assume 12 kg and 25 kg are the masses of each sack *and* their contents.
Answer: A mixture is a combination of two or more substances (elements or compounds) which is not done chemically. Mixtures are two types Homogeneous Mixtures and Heterogeneous mixtures.
