The graph is missing, however we can answer anyway.
In fact, this is the approximate percentage of the elements listed in the questions in the Earth's crust (data taken from wikipedia):
Iron 5.0 %
Calcium 3.6 %
Sodium 2.8 %
Potassium 2.6 %
Magnesium 1.5 %
of all of these, we see that the combination of two elements that makes up the closest number to 7% is calcium and sodium (3.6% + 2.8%=6.4%), therefore the correct answer is
Calcium and sodium.
The whiter the color the more young it is and the more energy it emits
Answer:
Work done = 0.3142 Nm
Explanation:
Mass of Object is 50 g
Circular path of radius is 10 cm ⇒ 0.1 m
Work done = Force × Distance = ?
*Distance moved (circular path) ⇒ Circumference of the circular path
2πr = 2 × 3.142 × 0.1 ⇒ 0.6284 m
*Force that is enough to move a 50 g must be equal or more than its weight.
therefore convert 50 grams to newton = 0.5 N
Recall that; work done is force times distance
∴ 0.5 N × 0.6284 m
Work done = 0.3142 Nm
