Answer:
Because the gravitational attraction of the Sun hold them in motion around it
Explanation:
For an object travelling in a straight path at constant velocity, the net force acting on the object must be zero.
The planets in the Solar System, however, do not experience a zero net force: in fact, the Sun exerts a gravitational attraction on them, whose magnitude is given by

where
G is the gravitational constant
M is the mass of the Sun
m is the mass of the planet
r is the average distance between the Sun and the planet
Due to the presence of this force, the Sun makes the planets 'deviating' from their straight path, forcing them to following an elliptical path around the Sun.
L=wavelength
L=0.032
c=Lf
f=c/L
f=3e8/0.032
f=9.375GHz
A.) conduction.
conduction is the process by which heat or electricity is directly transmitted through a substance when there is a difference of temperature or of electrical potential between adjoining regions, without movement of the material.
<u>Answer:</u> The remaining sample of X is 6.9 grams.
<u>Explanation:</u>
All the radioactive reactions follow first order kinetics.
The equation used to calculate rate constant from given half life for first order kinetics:

We are given:

Putting values in above equation, we get:

The equation used to calculate time period follows:

where,
= initial mass of sample X = 78 g
N = remaining mass of sample X = ? g
t = time = 16.5 min
k = rate constant = 
Putting values in above equation, we get:

Hence, the remaining amount of sample X is 6.9 g
Answer:
B
Explanation:
It absorbs gases, but also heat energy from the atmosphere, distributes them in its depths and thus slows down changes in the entire Earth system. The amount of energy absorbed by the ocean is therefore also an indication of the total heat absorbed by the planet.