Solution :
When the spacecraft is at halfway point, the distance from the Earth as well as Mars are same. We have to account the masses of the planets. The gravitational force that is exerted by the Earth is greater because of its combined mass with the space probe.
The mass of Earth is greater than the mass of Mars. Therefore, the force of Earth is more than Mars.
10 joules of work is done by the object
P = density × gravity acceleration × height
P = 1200 × 9.81 × 15/100
P = 1765.8
The physical model of the sun's interior has been confirmed by observations of neutrino and seismic vibrations.
<u>Explanation:</u>
Sun's interior is composed of very high temperature and solar flares. So it is very difficult to understand the interior of the sun. But by using the vibrations of neutrino and seismic waves emitted by the solar waves, the physical model can be assumed.
As the interior of the sun performs continuous chain of hydrogen cycle. So the continuous emission of energy from the chain reaction releases neutrino. So these vibrations in neutrino and seismic vibrations, the physical model can be assumed easily.
Option B i.e discretion is the right and correct answer.
[C]utting programs that were not effective or essential and even some that were, but are now unaffordable; and precisely targeting our investments. Every department will feel the impact of these reductions as they cut programs or tighten their belts to free up more resources for areas critical to economic growth.
—President Barack Obama,
2012 Budget Message of the President.
The President above clearly refers to the Discretion Spending where portion of the budget is decided by Congress through the annual appropriations.