Answer:
The geocentric model (also known as geocentrism, often exemplified specifically by the Ptolemaic system)
Convection is correct i think
- Different factors affect the position of the Sun on its daily path across the sky
Explanation:
Different factors affect the position of the Sun on its daily path across the sky. Earth rotates on a tilted axis and orbits the Sun in a slightly oval-shaped, or elliptical, path. These two motions affect the Sun's changing position in the sky and the times of daily sunrises and sunsets over a year.
The atlatl would have helped hunters throw a spear with enough force to take down larger animals.
From the physics side: this tool allowed the spear to be thrown with greater overall speed and acceleration = more accuracy and force.
There's multiple conditions that contribute so that trees can not grow in the tundra, but the most important one is the climate.
The climate in the tundra is very inhospitable. Most of the year is winter, and the soil is frozen, not just on the surface, but also deep into the ground, thus not allowing a tree to be able to develop a root system. Also, the winds are very cold and strong, so a young tree will not be able to withstand them and will break. The summer lasts for only few weeks, and it is not a proper summer, but relatively cold one, thus not enabling the conditions for a tree to be able to vegetate.