Answer:
Explanation:
Time dilation formula is
T = T₀ / √ 1-v²/c²
T₀ is time elapsed in moving reference , T time elapsed in stationary reference.
Here T₀ = 1 second
T = 1/√ 1-0.9² = 1/.4358 = 2.3 second
So 2.3 second will pass for each second on moving reference.
Answer:
The diameter of wire should be
m
Explanation:
Given:
Current density

Current
A
From the formula of current density,

Where
area of cylindrical wire = 



m
For finding the diameter of wire,

m
Therefore, the diameter of wire should be
m
Answer:
The force exerted by the child is 38.25 Newton
Explanation:
We use the formula F=mxa (m=mass and a= aceleration):
F= 45kg x 0,85 m/s2=38, 25 kgxm/s2= <em>38, 25 N</em>