Answer:
1) a = -1 m/s²
2) v = 12 m/s
Explanation:
Given,
The initial velocity of the object, u = 15 m/s
The final velocity of the object, v = 10 m/s
The time taken by the object to travel is, t = 5 s
Using the first equation of motion
v = u + at
a = (v - u) / t
Substituting the values
a = (10 - 15) / 5
= -1 m/s²
The negative sign indicates the body is decelerating
The acceleration of the object is, a = -1 m/s²
The speed of the object after 2 seconds
From the above equations of motion
v = 15 + (-1) 2
= 12 m/s
Hence, the speed of the object after 2 seconds is, v = 12 m/s