Academic- affect on substances, how it works
Scientific- helping cancer, making weapons
Answer:
Explanation:
Given
mass of box 
coefficient of kinetic friction 
coefficient of Static friction 
cart is moving with constant velocity therefore Net Force is zero
Since there is no net acceleration therefore friction force will be zero
mathematically

where 



Tidal energy is the form of energy used to generate electrical energy.
Answer:
The Physical Behavior of Objects when Gravity is Missing
In order to be able to form a concept of the general physical conditions existing in a weightless state, the following must be noted: the force of the Earth's gravity pulling all masses down to the ground and thus ordering them according to a certain regularity is no longer active.
Answer:
17. h = l − l cos θ
18. 1.40 m
Explanation:
Let's call d the height of the triangle. We can then say:
h = l − d
Using trig, we can write d in terms of l and θ:
d = l cos θ
h = l − l cos θ
If l = 6 m and l cos θ = 40°:
h = 6 − 6 cos 40
h ≈ 1.40