Answer:
Air pollution and water pollution.
Explanation:
The burning of coal causes air pollution, and coal fired power stations dump waste in large bodies of water.
3 Newtons toward the right because Newton’s second law:
F = ma
15N - 12N = ma
3N = ma
(With the right being the positive direction and the left the negative direction)
I would say 5.6 to the 4 and I’ll I did was add it to both side
Answer:t=0.81 s
Explanation:
Given
Penguin slides down with constant velocity of 3.57 m/s
as the Penguin Slides with constant velocity therefore 
is zero on Penguin
friction Force
coefficient of Kinetic friction
after reaching on floor final velocity of penguin will be zero after time t
thus
here 
(deceleration)
Answer:
Elements in a period have wide range of chemical properties.
Explanation:
- Period is the row of chemical elements's arrangement in the periodic table. It is numbered from 1 to 7.
- In period as we move towards right the atomic number of element constantly increases along with the change in chemical properties.
- As we move from left towards right in period, the valence electron number regularly increases in every element.
- This valence electron differs the reactivity of the elements.
