A Dodge Stealth is driving at 70 mph on a highway. It passes a BMW going the same direction. The BMW is moving 7 mph backward relative the Dodge. 63 mph is the velocity of the BMW
Answer: Option A
<u>Explanation:</u>
Given is the speed of the dodge stealth as 70 mph passing by the BMW moving with 7 mph relative to Dodge. Thereby, to calculate the velocity of BMW, relative velocity concept has to be employed.
As we know that the relative velocity tells us about relative velocity of mobile reference system as the difference or sum of the initial reference system.
Therefore,
velocity of the BMW = 
Velocity of the dodge = 
Velocity of the BMW with respect to dodge = 
As per the formula,
Answer:
Zero
Explanation:
Work done is given by multiplying force and distance moved. The distance is moved both positive and negative and it's equal distance. Since force used is the same hence work
W=F*d+ (F*-d)=0
Therefore, total work done is zero
d. the surface on which the object is moving is made smoother
This is called lubrication, I think ...
b. the weight of the moving object is decreased
If there is less araea of contact because of the weight reduction ("squeezing together") then this could also have an effexct. I thinl though the thrust of the q is on lubrication = oil, talcum powder, thin films of water etc
Please put answers in the comments of actual answers, as I need them! Lots of points! 63 points
KE = (1/2) (mass) (speed)²
KE = (1/2) (20 kg) (40 m/s)²
KE = (1/2) (20 kg) (1,600 m²/s²)
KE = (10 kg) (1,600 m²/s²)
KE = 16,000 Joules
This could be Hubble's law, or something related to it. I think there's a possibly Doppler RED SHIFT in the optical spectra of stars etc as observed on the earth. It seems that they are accelerating away from the earth, and that the further away they are the faster they are moving.
It seems that this has been connected to the idea of "The Big Bang" theory of the origin of the universe which seems to have superceded Professor Sir Fred Hoye's Steady State theory of the universe.
There's some Special Relativity in this lot, too.
