Answer:
0.2cm towards the retina.
Explanation:
the focal length of the frog eye is
(1/f) = (1/10) + (1/0.8)
f = 0.74cm
Since the distance of the object is 15cm Hence
(1/0.74) = (1/15) + (1/V)
V = 0.78cm
Therefore the distance the retina is to move is
0.78cm - 0.8cm = 0.02cm towards the retina.
Answer:
The ball reaches Barney head in 
Explanation:
From the question we are told that
The rise velocity is 
The height considered is 
The horizontal velocity of the large object is 
Generally from kinematic equation

Here s is the distance of the object from Barney head ,
u is the velocity of the object along the vertical axis which is equal but opposite to the velocity of the helicopter
So

So

= 
Solving the above equation using quadratic formula
The value of t obtained is 
The motion of the buoy consists of two independent motions on the horizontal and vertical axis.
On the horizontal axis, the motion of the buoy is a uniform motion with constant speed

. On the vertical axis, the motion of the buoy is a uniformly accelerated motion with constant acceleration

. The vertical position of the buoy at time t is given by

where h is the initial heigth of the buoy when it is released from the plane. At the time t=21 s, the buoy reaches the ground, so y(21 s)=0. If we substitute these two numbers inside the equation, we can find the value of h, the vertical displacement from the plane to the ocean:

The basic relationship between frequency and wavelength for light (which is an electromagnetic wave) is

where c is the speed of light, f the frequency and

the wavelength of the wave.
Using

and

, we can find the value of the frequency:
Answer:
2805 °C
Explanation:
If the gas in the tank behaves as ideal gas at the start and end of the process. We can use the following equation:
The key issue is identify the quantities (P,T, V, n) in the initial and final state, particularly the quantities that change.
In the initial situation the gas have an initial volume
, temperature
, and pressure
,.
And in the final situation the gas have different volume
and temeperature
, the same pressure
,, and the same number of moles
,.
We can write the gas ideal equation for each state:
and
, as the pressure are equals in both states we can write
solving for
(*)
We know
= 935 °C, and that the
(the complete volume of the tank) is the initial volume
plus the part initially without gas which has a volume twice the size of the initial volume (read in the statement: the other side has a volume twice the size of the part containing the gas). So the final volume 
Replacing in (*)