To solve this problem we will apply the concept of magnification, which is given as the relationship between the focal length of the eyepieces and the focal length of the objective. This relationship can be expressed mathematically as,

Here,
= Magnification
= Focal length eyepieces
= Focal length of the Objective
Rearranging to find the focal length of the objective

Replacing with our values


Therefore the focal length of th eobjective lenses is 27.75cm
Answer:
223.25
Explanation:
The thermal conductivity of an object is defined as the measure or the ability of the object to transfer heat or conduct heat through its body.
In the context, the thermal conductivity of the material is given as

And it is given that :
1 Btu = 1055 J
1 ft = 0.3048 m

We know that 1 h = 3600 s
So the thermal conductivity of the material in
is :
Thermal conductivity :


= 223.25
Answer:
t = 0.657 s
Explanation:
given,
initial vertical velocity = 7.5 m/s
initial horizontal velocity = 0 m/s
angle = 49◦
using kinetic equation
final velocity in vertical direction
v sinθ = u_y - gt ........................(1)
final velocity in horizontal direction
v cosθ = u_x + a_x × t
here u_x = 0.0 m/s
v cosθ = a_x×t ......................(2)
Dividing equation (1) / (2)

solving for time t

u_y = initial velocity along x direction
acceleration along a_x = 1.4 m/s²
g = acceleration due to gravity = 9.8 m/s²
θ = 43° , u_y = 7.5 m/s

t = 0.657 s
time taken by the particle is t = 0.657 s