Answer:
456.4 N
Explanation:
From conservation of energy, the potential energy is converted to kinetic energy hence
mgh=½mv²
Making v the subject then
[tex]v=\sqrt {2gh}[/tex]
Where g is acceleration due to gravity and h is height whike v is final velocity. Substituting 4.9m for h and 9.81 m/s² for g then
[tex]v=\sqrt {2\times 9.81\times 4.9}=9.80499872514015m/s\approx 9.8 m/s[/tex]
Change in momentum equals to the impulse.
Impulse, I= Ft
Change in momentum, ∆p= m(v-u)
Ft=m(v-u) making F the subject of formula then
[tex]F=\frac {m(v-u)}{t}[/tex]
Where F is force in Newton, t is time in seconds, m is mass of diver, v and u are the final and initial velocities respectively.
Substituting 68 kg for m, 9.8 m/s for v, 0 m/s for u since it is initially at rest and 1.46 s for t
[tex]F=\frac {68(9.8-0)}{1.46}=456.43835616438N\approx 456.4N[/tex]