The law of floatation states that, a floating body displaces its own weight of the fluid in which it floats.
The initial kinetic energy of the car is

Then, the velocity of the car is decreased by half:

so, the new kinetic energy is

So, the new kinetic energy is 1/4 of the initial kinetic energy of the car. Numerically:
Answer:
2.5
Explanation:
The capacitance of a parallel-plate capacitor filled with dielectric is given by

where
k is the dielectric constant
is the capacitance of the capacitor without dielectric
In this problem,
is the capacitance of the capacitor in air
is the capacitance with the dielectric inserted
Solving the equation for k, we find


Explanation:
Newton's 2nd Law can be expressed in terms of the object's momentum, in this case the expelled exhaust gases, as
(1)
Assuming that the velocity remains constant then

Solving for
we get

Before we plug in the given values, we need to convert them first to their appropriate units:
The thrust <em>F</em><em> </em> is

The exhaust rate dm/dt is


Therefore, the velocity at which the exhaust gases exit the engines is

