Why do you think European explorers travelled with cannons and arnaments (guns, swords), and other weapons on their vessels?

One of the brightest comets of the 20th century was comet hyakutake, which passed close to the sun in early 1996. the orbital period of this comet is estimated to be about 30,000 years. find the semi-major axis of this comet’s orbit. compare it to the average sun-pluto distance and to the distance to alpha centauri, the nearest star to the sun, which is 4.3 light-years distant.

Can someone me with this plz? ! i'm putting 20 points on it!

What would have happened to portugal’s trade if they had not found a way to sail around the tip of africa