Question

r = 7t-1 then find (a) velocity at t=1 second and acceleration at t=2 second

Answer 1

r = 7t - 1
Differtiating both sides with respect to time
dr/dt = d(7t-1)/dt
velocity = d(7t)/dt - d(1)/dt
v = 7 - 0
v = 7
Therefore velocity at any time is 7
Velocity at t=1 is 7 m/s

Acceleration = dv/dt
=d(7)/dt
=0
Therefore acceleration = 0

Therefore velocity = 7 and acceleration = 0