What is its speed after 1.22 s if it accelerates uniformly at −2.14 m/s 2 ? Answer in units of m/s.?
2.14 m/s^2 for 1.22 s is 2.6108 m/s. That's the change in speed, but you didn't give the starting speed.
Time (t) = 1.22 sec
Acceleration (a) = - 2.14 m/sec²
Final Speed (V) = ?
Let, it was starting from rest, then
Initial speed (u) = 0 m/s
Using Kinematic Relation:
V = u + at
V = 0 + (-2.14) × 1.22
V = - 2.61 m/sec
Can't answer without knowing the initial speed. The relevant equation is:
v = u + at