Question

An electron has a constant acceleration of +3.3 m/s2. at a certain instant its velocity is +8.6 m/s. what is its velocity (a) 2.3 s earlier and (b) 2.3 s later?

Answer 1

Hello!


The velocity function is:

$\mathsf{V = V_0 + at}\\ \\ \mathsf{V = 8.6 +3.3t}$


a) 2.3 s earlier, we can make t = -2.3 s, in relation to our initial time:

$\mathsf{V = 8.6 + 3.3\cdot(-2.3)}\\ \\ \mathsf{V = 8.8-7.59}\\ \\ \boxed{\mathsf{V = 1.21 \ m/s}}$

b) Now we can make t = 2.3 s:

$\mathsf{V = 8.6 + 3.3\cdot2.3}\\ \\ \mathsf{V = 8.6 + 7.59}\\ \\ \boxed{\mathsf{V = 15.59 \ m/s}}$