Answer:
Ultraviolet rays from sun are very harmful from skin and can cause sunburn and skin diseases especially ultraviolet B rays.<em> A sunscreen lotion act as a protection barrier on the skin that restrict the direct contact of UV rays with skin and filter the harmful rays to enter the skin. </em>
Radiotherapy is a medical therapy use to treat cancer. <em>Radiotherapy commonly uses x-rays and gamma rays because they are high-energy particles or waves that kills or destroys the cancer cells.</em>
Answer:
false
Explanation:
Elastic collision: the collision is said to be elastic if the kinetic energy is conserved during the collision.
If the kinetic energy is not conserved, then the collision is not elastic.
So, here no information is given so we cant say about the type of collision.
So, it is False.
Answer:
c
Explanation:
energy doesnt affect to mass of a object
Answer:
(a) 
(b) 
Explanation:
Given data
The angular velocity of two cylinders ω=257 rad/s
The mass of the two cylinders m=2.88 kg
The radius of small cylinder r₁=0.319 m
The radius of larger cylinder r₂=0.605 m
For Part (a)
The rotational kinetic energy of the cylinder is given by:

Where I is rotational of inertia of solid cylinder about its central axis.
So

Substitute the given values
So

For Part (b)

Substitute the given values

Answer:
KE= 1/2 * mass * Velocity^2
Explanation:
1/2 * 72.0kg* 79^2 m/s = 224676 J