When a car hits you in a rear end collision, the car initially has a momentum going in one direction. This causes your car to move in the same direction that car was moving even if you were at rest. So, for conservation of momentum, you initially have momentum going in the east direction for example, after the collision, you will have a change in momentum which causes you to have a velocity in the west direction. This is because you are initially at rest and then there is a sudden change in velocity so when you speed up, that momentum causes you to move backwards. If you don't have a properly adjusted neckrest you could may experience whiplash.
Answer: 26.84 m/s
Explanation:
Given
Original frequency of the horn 
Apparent frequency 
Speed of sound is 
Doppler frequency is

Where,

Insert values
![\Rightarrow 246=228\left[\dfrac{340+v_o}{340-0}\right]\\\\\Rightarrow 366.84=340+v_o\\\Rightarrow v_o=26.8\ m/s](https://tex.z-dn.net/?f=%5CRightarrow%20246%3D228%5Cleft%5B%5Cdfrac%7B340%2Bv_o%7D%7B340-0%7D%5Cright%5D%5C%5C%5C%5C%5CRightarrow%20366.84%3D340%2Bv_o%5C%5C%5CRightarrow%20v_o%3D26.8%5C%20m%2Fs)
Thus, the speed of the car is 
Answer:

Explanation:
First calculate the mass of the asteroid. To do so, you need to find the volume and know the density of iron.
If r = d/2 = 645ft, then:


In order to find force, use Newton's universal law of gravitation:

Where,
G= the gravitational constant:


Our data are,
State 1:

State 2:

We know as well that 
To find the mass we apply the ideal gas formula, which is given by

Re-arrange for m,

Because of the pressure, temperature and volume ratio of state 1 and 2, we have to

Replacing,

For conservative energy we have, (Cv = 0.718)

if it is heat flow through a metal, it would be necessary to have a conductor so that the electrons can flow through it (delocalised electrons).
In terms of radiation, it would require a good absorber of heat (e.g. a black surface) so that the thermal energy flows through on the surface area.