ANSWER:
D) centripetal acceleration.
STEP-BY-STEP EXPLANATION:
When a body performs a uniform circular motion, the direction of the velocity vector changes at every instant. This variation is experienced by the linear vector, due to a force called centripetal, directed towards the center of the circumference that gives rise to the centripetal acceleration.
Therefore, the answer is centripetal acceleration.
X-rays are high energy electrons
that can cause damage when exposed under extreme conditions. The best technology
that can block it is using a lightweight type of metal foam. It can take in
high energy collisions which also exhibits high forces. it does not only block
x-rays but also, neutron radiation and gamma rays.
(C) 200 N
Explanation:
The acceleration due to gravity on earth 
is given by
where 
= universal gravitational constant
= mass of the earth
= radius of the earth
Planet Krypton has twice the mass of earth and 3 times the radius so its acceleration due to gravity 
is
or
If we multiply both sides by Superman's mass, we get his weights on both planets:
You should write meter per second square for the acceleration in words
