Answer
(a) 8030 J (b) 2010 J (c) 32.1kJ
Work Step by Step
(a) The formula for kinetic energy is equal to $$K=\frac{1}{2}mv^2$$ Substituting known values of $m=9.50g=0.00950kg$ and $v=1.30km/s=1300m/s$ yields a kinetic energy of $$K=\frac{1}{2}(0.00950kg)(1300m/s)^2=8030J=8.03kJ$$ (b) If the speed is halved, the kinetic energy becomes $$K=\frac{1}{2}m(\frac{v}{2})^2=\frac{1}{8}mv^2=\frac{1}{4}K_o=\frac{1}{4}(8030J)=2010J$$ (c) If the speed is doubled, the kinetic energy becomes $$K=\frac{1}{2}m(2v)^2=2mv^2=4K_o=4(8030J)=32.1kJ$$
