(a) The time taken for the projectile to reach the maximum height is 32.65 s.
(b) The horizontal range of the projectile is 9,049.1 m.
The given parameters:
- Initial velocity of the projectile, u = 320 m/s
- Angle of projection, = 30 degrees
The time taken for the projectile to reach the maximum height is calculated as follows;

The horizontal range of the projectile is calculated as follows;

Learn more about horizontal range here: brainly.com/question/12870645
C. Gamma rays have more energy than infrared rays
Answer:
9.949 m
Explanation:
From the question,
L' = L+LαΔT................. Equation 1
Where L' = New length, L = Original length, α = linear expansivity of Cu, ΔT = change in temperature
Given: L = 10 m, α = 0.00017 K⁻¹, ΔT = 50-80
L' = 10+10(0.00017)(50-80)
L' = 10-0.051
L' = 9.949 m
Hence the new legth of Cu is 9.949 m
All you would do is for a, 10 times 2 is 20 so it would be 20-dB
For b, 10 times 4 is 40 so it would be 40-dB
For c, 10 times 8 is 80 so it would be 80-dB
Velocity is speed plus direction