The man who jumps from the bridge falls 5[s] before impact. Determine
a) his speed at the time of impact
b) his acceleration if the impact lasted only 0.1
[s]
c)height of the bridge

Question

The man who jumps from the bridge falls 5[s] before impact.  Determine
a) his speed at the time of impact
b) his acceleration if the impact lasted only 0.1  
[s]
c)height of the bridge

anonymous · Answer

$$v _{f}=v _{i} + at=0+9.8m/s^{2}(5s)=49m/s$$$$a=\Delta v/\Delta t=\frac {0-49m/s} {0.1s}=-490m/s^{2}$$$$h = \frac {(v _{f}^{2} - v _{i}^{2})} {2a}=\frac {(49m/s)^{2}} {19.6m/s^{2}}=122.5m$$