Muscles in animals are often found in pairs, because
a. muscles can only produce a force as they relax.
b. muscles can only pull.
c. muscles need to be able to both push and pull.
d. muscles can only push.

What is the final velocity of the initial velocity of 25 and -50?

How will the system respond to a temperature increase?

(2) (a) you have a simple circuit that consists of only a battery (δvbat=1.5v) and two resistors with resistance r1=10ω and r2=5ω, connected in series with each other. what is the current running through the battery? (b) you re-arrange your circuit so now r2 is attached in parallel to r1 rather than in series. what is the current running through the battery? (c) you add an additional resistor r3=7ω on the same branch as r2. what is the current running through the battery? (d) what is the power dissipated in r3?