For elbow flexion: a. triceps brachii is the synergist and biceps brachii is the antagonist.
b. biceps brachii is the antagonist and triceps brachii is the agonist.
c. biceps brachii is the agonist and triceps brachii is the antagonist.
d. biceps brachii is the synergist and triceps brachii is the agonist.
e. deltoid is the agonist and biceps brachii is the synergist.

c. biceps brachii is the agonist and triceps brachii is the antagonist.

Explanation:

The triceps is the antagonist because it is on the opposite side of the elbow joint and has the potential to oppose the elbow flexion.

1. H

2. C

Explanation:

for #1 I chose H because mass doesn't change

for #2 I chose C because the longer arrow is greater force while the smaller is less force. The weaker force pushes the object down but the greater force would push greater. For A, the object wouldn't move. For B and D, the object would move down.