Aluminum foil (I think, it may not be right)
Answer:
Reflective
Explanation:
The radiation pressure of the wave that totally absorbed is given by;

and While the radiation pressure of the wave totally reflected is given by;

Now compare the two-equation you can clearly see that the pressure due to reflection is larger than absorption therefore the sail should be reflective.
Answer:
c. 
Explanation:
= Initial distance between asteroid and rock = 7514 km = 7514000 m
= Final distance between asteroid and rock = 2823 km = 2823000 m
= Initial speed of rock = 136 ms⁻¹
= Final speed of rock = 392 ms⁻¹
= mass of the rock
= mass of the asteroid
Using conservation of energy
Initial Kinetic energy of rock + Initial gravitational potential energy = Final Kinetic energy of rock + Final gravitational potential energy

Your answer would be A. You divide 96 by 16 to find the answer
Let the rescue boat starts at an angle theta with the North
now its velocity towards East is given as


now in some time "t" it will catch the boy
so we will have

also we have

now we have



by solving above we got
