Answer:
a) 60 N
b) 860 N
Explanation:
Given that,
= 100 kg
= 20 kg
= 8.0 
= 3.0
a) By Newton's Law,
∑
∑
Hence,
b) By Newton's Law
∑
Hence,
Net force acting on 100 kg mass,
Answer:
The answer is b, friction.
Explanation:
Let's say you're riding your roller skates on the sidewalk. The surface of the sidewalk rubs against your skates, counteracting your movement while you proceed in the opposite direction that the sidewalk is counteracting. The force that causes that is friction.
The amount left of a given substance can be calculated through the equation,
A = (A0) x 0.5^n/h
From the given scenario,
A/A0 = 0.75 = 0.5*(60/h)
The value of h from the equation is 144.565 minutes.
This column actually appears due to the body parts reflecting the light of the sun or moon to the observer.
If the body is not perfectly smooth, only parts of this body would be at the correct position to reflect the light of the sun or moon to the observer.
If the body was perfectly smooth, it would act like a mirror where you can see the full image of the sun or the moon reflected on it.
