Question

3.

Answer 1

Answer:

a) a = 1 [m/s²]

b) a = 0.25 [m/s²]

Explanation:

To solve this problem we must use the following equation of kinematics.

a)

Between 0 and 2 seconds

$v_{f} =v_{o}+a*t$

where:

Vf = final velocity = 2 [m/s]

Vo = initial velocity = 0

a = acceleration [m/s²]

t = time = 2 [s]

Note: the positive sign of acceleration in the previous equation allows us to appreciate that the velocity is increasing

2 = 0 + a*2

a = 2/2

a = 1 [m/s²]

b)

Between 2 and 4 seconds

$v_{f} =v_{o} +a*t$

where:

Vf = final velocity = 2.5 [m/s]

Vo = initial velocity = 2

a = acceleration [m/s²]

t = time = (4 - 2) = 2 [s]

2.5 = 2 + a*2

2.5 - 2 = 2*a

0.5 = 2*a

a = 0.25 [m/s²]