When an astronaut travels from the earth to the moon, her weight changes, but her mass remains constant. <em>(C ).</em>
<span>d. 93 billion miles
</span>Earth, being the third planet from the sun is unique in the universe because it is currently the only planet known to support life. Earth's distance from the sun is really one of the key reasons why it is has widespread life.Earth occupies what scientists sometimes call the Goldilocks zone. Its distance from the sun means its neither too hot nor too cold to support liquid water. Water is thought to be a key ingredient for life.<span> The energy from the sun in just the right intensity and the availability of water on the earth make it possible for life to thrive on earth. Plants use both these resources for photosynthesis and make nutrients that are available to support the life of animals on the earth. </span>
Answer:
60 cm
Explanation:
We are given;
- Focal length of a concave mirror as 30.0 cm
- Object distance is 15.0 cm
We are required to determine the radius of curvature.
We need to know that the radius of a curvature is the radius of a circle from which the curved mirror is part.
We also need to know that the radius of curvature is twice the focal length of a curved mirror.
Therefore;
Radius of curvature = 2 × Focal length
Therefore;
Radius of curvature = 2 × 30 cm
= 60 cm
Convection is the circular motion that occurs as hotter air or liquid increases when the cooler air or liquid drops down, and has faster moving molecules, rendering it less dense. Convection currents within the earth shift layers of magma, and currents are formed by convection in the ocean.