2. a 100 kg box initially traveling at 10 m/s encounters a frictional force and takes 5 seconds to
slow down to a stop.
a. determine the acceleration of the box (direction matters + or -)
b. if friction is the only unbalanced force, what is its value?

a. -2 m/s²

b. -200 N

Explanation:

2a.

Given:

v₀ = 10 m/s

v = 0 m/s

t = 5 s

Find: a

v = at + v₀

(0 m/s) = a (5 s) + (10 m/s)

a = -2 m/s²

2b.

Newton's second law:

∑F = ma

F = (100 kg) (-2 m/s²)

F = -200 N

a charge 3q is at the origin, and a charge −2q is on the positive x axis at x=a. part a where on the x-axis would you place a third charge so it would experience no net electric force? enter an expression for the exact answer, which will involve a square-root sign. (do not enter an approximate decimal answer.)