Answer:
19 cm sq
Explanation:
you have to count one full and half area occupied by leaf in each box, then you have to multiply with 1 cm sq.
Answer:
B. Chemical changes involve the formation of a new substance.
Explanation:
They can both release energy, both can be measured, and chemical changes can be caused by oxygen, so I believe it would be B.
Answer:
Uniform circular motion
Explanation:
When a car is moving with constant speed along a curve, it will said to have uniform circular motion. The speed of the car remains constant in this case. But its velocity keeps on changing. The velocity can be calculated by drawing the tangent on the circle. Hence, the motion of the car is uniform circular motion.
Answer: D. An action-reaction force pair
Explanation: When you sit in your chair, your body exerts a downward force on the chair and the chair exerts an upward force on your body. There are two forces resulting from this interaction - a force on the chair and a force on your body. Another example would be a person pushing against a wall (action force), and the wall exerts an equal and opposite force against the person.
Explanation:
Given that,
The disintegration constant of the nuclide, 
(a) The half life of this nuclide is given by :



(b) The decay equation of any radioactive nuclide is given by :


Number of remaining sample in 4.44 half lives is :


So, 

(c) Number of remaining sample in 14.6 days is :


So, 

Hence, this is the required solution.