Answer:
A: 
Step-by-step explanation:
Acceleration is second derivative of position, velocity is first derivative. Therefore, the velocity is the integral of acceleration.

Integrate:

V(0)=-5:

Therefore, v(t):

Answer:
u=9.8
Step-by-step explanation:
the minus sign on u and the minus sign on 9.8 cancel out so you get u=9.8.
Answer: Nick must now at least 6 yards.
Step-by-step explanation:
Since Nick has $80 saved already, and he makes $40 per yard that he mows, thus can be put up in an equation as:
= 80 + 40y
where y = number of yards
Since Nick needs to raise at least $320 for his trip, the equation to solve this will be:
80 + 40x ≥ 320
40x ≥ 320 - 80
40x ≥ 240
x ≥ 240/40
x ≥ 6
Therefore, Nick must now at least 6 yards.