It was a punishment after the episode of the spies (Numbers ch.13-14).
Presumably, yes.
Forty years (Numbers ch.14)
God cursed the Israelites to wander the wilderness for 40 years as a consequence of their lack of faith and disobedience. This period served as a time of purification and repentance for the Israelites before entering the promised land.
The book of Numbers in the Bible primarily contains census data of the Israelites, detailing the organization and numbers of the tribes as they wander in the wilderness. It also includes various laws and regulations given to the Israelites by God through Moses, as well as accounts of their experiences and challenges during their time in the wilderness.
Forty years.
Because of the episode of the spies (see Numbers ch.13-14). See this link for details on this and other related topics :http://judaism.answers.com/kosher/the-complaints-in-the-wilderness-and-the-golden-calf
because the Israelite's disobeyed God, that's why they had to wander for forty days in the wilderness
The number of israelites killed in the wilderness were many. as the bible says the entire generation of people who made the golden calf walked and died in the wilderness.
Moses.
who were the people wandering in the wilderness
As the Israelite were made to wander in the wilderness for a period of 40 yeards as they had failed God by grumbling and mistrusting both Moses as well as God. They even built a Golden calf while Moses went to collect the ten commandments.So that entire generation who did it did not reach the promised land of Canaan.
Because God was reprimanding them after the events when the Scouts were sent to scout out the Holy Land. The Israelites did not exhibit complete trust in God (Deuteronomy ch.1). See Numbers ch.13-14. The forty years that God had them spend in the wilderness gave enough time for a new generation to be born; and it gave the nation time to completely learn and absorb the Torah, since they as yet had no other occupation.