Answer:
520 miles per hour
Explanation:
Let the speed of the Boeing 747 be x miles per hour.
The small airplane covers distance of 780 miles with speed 260 miles per hour.
Also,
After 1.5 hours the Boeing 747 leave the same place and reaches at same time. Both covered distance of 780 miles.
So,
<u>Time taken by Boeing 747 + 1.5 hours = Time taken by small plane.</u>
Also,
Time = Distance/ speed
So,
780 / x + 1.5 = 780/ 260
Solving for x, we get:
<u>x = 520 miles per hour</u>
We know average speed =total distance/time taken
So avg speed=(85+63)/(5+5)=14.8km/hr
Explanation:
Geocentric model said that the Earth is at the center of the universe and everything revolves around it. It was considered to be stationary. Galileo proved this model incorrect with the help of his astronomical observations. Some of the key observation that he used to support the heliocentric model were:
1. He proposed the theory that the tides on the Earth occur because of its motion.
2. He observed the phases of the Venus which meant that the Venus revolved around the Sun and not the Earth.
3. He observed other planets and thus noted that they also move around the Sun and not Earth.
4. He discovered the Moons of other planets.
Become more positive instead of negative
Resistance reduces the current. If there is more resistance, there is less current.