Answer: f = - 0.50 m, negative (diverging) lens
Explanation: D-value (diopter ) means 1/f, unit is 1/m. Thus -2.0D
Means f = ( 1/ -2.0 ) m = -0.50 m
Answer:

29010.53917 m
Explanation:
= Density of asteroid = 2 g/cm³
V = Volume
d = Diameter = 10 km
r = Radius = 
v = Velocity = 11 km/s
= Heat vaporization of water = 
= Change in temperature = 100-20
Mass is given by

The kinetic energy is

Heat is given by

Mass of water is 
Volume is 
Amount of water is 
If it were a cube

The height of the water would be 29010.53917 m
Answer:
Power = 50204 [watts]
Explanation:
We know that the power is defined by the following expression:
Power = Work/time
where:
Power [watts]
time [seconds]
The work done will be the following:
Work = Force * distance [Joules]
Force[Newtons]
distance[meters]
Force = mass* gravity
Force=290 [kg]*9.81[m/s^2] =2844.9[N]
Work = 2844.9[N]*300[m] = 853470[J]
Therefore
Power = 853470 / 17 = 50204 [watts]