Answer:
The length and the magnification of this telescope are 41 cm and 0.108.
Explanation:
Given that,
Focal length of first lens f= 4.0 cm
Focal length of other lens f'= 37 cm
We need to calculate the length of the telescope
Using formula of length

Put the value into the formula

We need to calculate the magnification of the telescope
Using formula of the magnification

Put the value into the formula


Hence, The length and the magnification of this telescope are 41 cm and 0.108.
Answer:
#_time = 7.5 10⁴ s
Explanation:
In order for the astronaut to be younger than the people on earth, it follows that the speed of light has a constant speed in vacuum (c = 3 108 m / s), therefore with the expressions of special relativity we have.
t =
where t_p is the person's own time in an immobile reference frame,

let's calculate
we assume that the speed of the space station is constant
t_ = 0.99998666657 s
therefore the time change is
Δt = t - t_p
Δt = 1 - 0.9998666657
Δt = 1.3333 10⁻⁵ s
this is the delay in each second, therefore we can use a direct rule of proportions. If Δt was delayed every second, how much second (#_time) is needed for a total delay of Δt = 1 s
#_time = 1 / Δt
#_time =
#_time = 7.5 10⁴ s
Answer:
Explanation:
Considering Work done by friction is asked
Given
mass of block 
force 
inclination 
block is displaced by 
coefficient of kinetic friction 
Friction force 
Normal reaction 

Friction Force 
Work done by friction force

Because almost all of the force is done by the weight of the person and the mechanism of the swing itself, when you push someone you only give them an increase in velocity, the acceleration comes from the weight at first and then from gravity when the person is coming down, which is why we bend our legs when coming down