Answer:
6.5 m/s^2
Explanation:
The net force acting on the yo-yo is
F_net = mg-T
ma=mg-T
now T= mg-ma
net torque acting on the yo-yo is
τ_net = Iα
I= moment of inertia (= 0.5 mr^2 )
α = angular acceleration
τ_net = 0.5mr^2(a/r)
Tr= 0.5mr^2(a/r)
(mg-ma)r=0.5mr^2(a/r)
a(1/2+1)=g
a= 2g/3
a= 2×9.8/3 = 6.5 m/s^2
Answer:
80% (Eighty percent)
Explanation:
The material has a refractive index (n) of 1.25
Speed of light in a vacuum (c) is 2.99792458 x 10⁸ m/s
We can find the speed of light in the material (v) using the relationship
n = c/v, similarly
v = c/n
therefore v = 2.99792458 x 10⁸ m/s ÷ (1.25) = 239 833 966 m/s
v = 239 833 966 m/s
Therefore the percentage of the speed of light in a vacuum that is the speed of light in the material can be calculated as
(v/c) × 100 = (1/n) × 100 = (1/1.25) × 100 = 0.8 × 100 = 80%
Therefore speed of light in the material (v) is eighty percent of the speed of light in the vacuum (c)
If it is a multiple choice question is C. Infrared waves do not carry enough energy to kill cancerous cells.
Answer:

Explanation:
Aceleration is a change on the velocity of the object in a given time.
For this case: the initial velocity is

and the final velocity is :

so, the change in velocity is:

and the change in time , according to the problem:

So, the aceleration is:

Answer:
option B.
Explanation:
The correct answer is option B.
The phenomenon of the curtains to pull out of the window can be explained using Bernoulli's equation.
According to Bernoulli's Principle when the speed of the moving fluid increases the pressure within the fluid decrease.
When wind flows in the outside window the pressure outside window decreases and pressure inside the room is more so, the curtain moves outside because of low pressure.