Answer:
41°
Explanation:
Kinetic energy at bottom = potential energy at top
½ mv² = mgh
½ v² = gh
h = v²/(2g)
h = (2.4 m/s)² / (2 × 9.8 m/s²)
h = 0.294 m
The pendulum rises to a height of above the bottom. To determine the angle, we need to use trigonometry (see attached diagram).
L − h = L cos θ
cos θ = (L − h) / L
cos θ = (1.2 − 0.294) / 1.2
θ = 41.0°
Rounded to two significant figures, the pendulum makes a maximum angle of 41° with the vertical.
Complete Question
The complete question is shown on the first uploaded image
Answer:
a

b

Explanation:
From the question we are told that
The image distance is 
The value of the image is negative because it is on the same side with the corrective glasses
The object distance is 
The reason object distance is because the object father than it being picture by the eye
General focal length is mathematically represented as

substituting values

=> 
Generally the power of the corrective lens is mathematically represented as

substituting values


<span>Nitrogen is used to protect steel from water because nitrogen has stable physical properties that enables the nitrogen to be resistant to water molecules. Nitrogen also serves as a coat for the steel to not be corroded easily</span>
Try this solution (if it is possible, check it in other sources):
1. for m_Tarzan=75kg., initial_height=4m., end_height=0 m. and g=10 N/kg. Energy is:

2. The same value of Energy is applied for m_Tarzan+Jane=75+50=125 kg.:

3. According to the formula of the Speed:
Speed=sqrt(6000/125)=sqrt(48)=4sqrt(3)≈4*1.71=6.84 (m/s)
Answer: 6.84 (m. per sec.)