course phy121

Make up a problem for situation # 1, and solve it using direct reasoning. v0=0m/s

vF=10m/s

a=2.5m/s/s

vAve = (v0 + vF) / 2

5 = (0 + 10) / 2

a = `dv/`dt

`dv / a = `dt

10 / 2.5 = 4sec

`dt * vAve = `ds

4sec * 5m/s = 20cm

vAve=5m/s

`dt=4sec

`ds=20cm

Make up a problem for situation # 8, and solve it using the equations of uniformly accelerated motion.

vF = 6m/s

a = 1m/s/s

`ds = 20cm

v0^2 = (vF^2 - 2a) / `ds

1.3^2 = (36 - 2*1) / 20

vAve = (v0 + vF) / 2

3.65 = (1.3 + 6) / 2

`ds = {(v0+vF)/2} * `dt

`ds / {(v0+vF)/2} = `dt

20 / {(1.3 + 6)/2} = 5.48

v0 = 1.3m/s

vAve=3.65m/s

`dt=5.48sec"