C. It is a chemical change due to the change in temperature and gas production
Answer:
μ= 0.3
Explanation:
Given that
F= 33 N
m = 11 kg
Given that crate is moving with constant velocity is means that acceleration of the crate is zero.If acceleration of the system is zero then the total force on the system will be balance.
Therefore
F= Friction force
F= μ m g
μ=Coefficient of friction
33 = μ x 10 x 11 ( take g= 10 m/s²)
3 = 10 μ
μ= 0.3
Therefore coefficient of friction will be 0.3 .
Answer:
a. The magnitude of the tension in the string is greater than the magnitude of the weight of the rock.
Explanation:
During the motion of the rock while it is in downward motion we can say

since it is performing circular motion so we will have its acceleration towards its center



So at the lowest point of the path we can say

so correct answer is
a. The magnitude of the tension in the string is greater than the magnitude of the weight of the rock.
Work = Force multiplied by the distance(or displacement)