Answer:
180
Explanation:
1) E=F*L, where E - energy of the baseball, F - the required force, L - backward moving (0.35m);
2) E=mV²/2, where E - energy of the baseball, m - the mass of the baseball (0.14kg), V - the velocity of the baseball (30m/s).
3) if E=F*L and E=mV²/2, then F*L=mV²/2, from which
[tex]F=\frac{mV^2}{2L};[/tex]
4) according to the last formula
[tex]F=\frac{0.14*900}{2*0.35}=\frac{126}{0.7}=180(N).[/tex]
