Answer:
Astronomer
Explanation:
A scientist who studies the objects in the sky, including planets, galaxies, black holes, and stars, is called an astronomer. These days, the terms astronomer and astrophysicist are used interchangeably, to talk about any physicist who specializes in celestial bodies and the forces that affect them.
<h2><u>We have</u>,</h2>
- Initial velocity (u) = 0 m/s
- Time taken (t) = 2.9s
- Acceleration due to gravity (g) = + 10 m/s² [Down]
<h2><u>To calculate</u>,</h2>
- Final velocity (v)
- Height (h)
<h2><u>Solution</u><u>,</u></h2>
→ v = u + gt
→ v = 0 + 10(2.9)
→ v = 29 m/s
… ( Ans )
And,
→ h = ut + ½gt²
→ h = 0(2.9) + ½ × 10 × (2.9)²
→ h = 5 × 8.41
→ h = 42.05 m
… ( Ans )
Answer:
0.016 s
Explanation:
Initial velocity, u = 0
use the third equation of motion to find the acceleration of the rock.

Net displacement in the vertical direction would be zero. y = 0
Use second equation:

Thus, the rock will return to its initial release point in 0.016 s.