Answer:
0.125 cm
Explanation:
1/f = 1/d¡ + 1/d。
Find the focal point
(13.0^-1 + 20.8^-1) = 0.125 m
Focal point = 0.125 m
Answer:
The value of tangential acceleration
40 
The value of radial acceleration 
Explanation:
Angular acceleration = 50 
Radius of the disk = 0.8 m
Angular velocity = 10 
We know that tangential acceleration is given by the formula

Where r = radius of the disk
= angular acceleration
⇒
0.8 × 50
⇒
40 
This is the value of tangential acceleration.
Radial acceleration is given by

Where V = velocity of the disk = r 
⇒ V = 0.8 × 10
⇒ V = 8 
Radial acceleration


This is the value of radial acceleration.
Answer:
C. Increasing its buoyancy

= (18 x 10^-6 /°C)(0.125 m)(100° C - 200 °C)
= -0.00225 m
New length = L + ΔL
= 1.25 m + (-0.00225 m)
= 1.248
D
I think the answer is 4) All of the above!! :)