Why was Cassini launched toward Venus if it is going to explore Saturn? The gravity of Venus will boost the speed of the space probe

The orbit of Venus is between Earth and Saturn

Venus is needed to reflect the radio signals to the probe

Aspaceship starting from a resting position accelerates at a constant rate of 9.8 meters per second per second. how far will the spaceship travel if its final speed is 1 percent the speed of light (300,000,000 m/s)? a. 3.1 × 106 m b. 2.94 × 108 m c. 7.8 × 1010 m d. 4.6 × 1013 m