Stop using it all the time for some useless things.
Yes. Think of block sitting on top of a bigger block. If the bottom block moves, it will drag the top block with it. Since the force of friction on the small block and its displacement are in the same direction, the "work" is positive. The static friction is a passive force, It is not a source of energy; it transmits the force placed on the bottom block. (And the "work" done by the friction on the bottom block is exactly the negative of the work done on the top block.)
A, yes because the plane is using air resistance and acceleration is increasing while it goes up. Although you don’t know speed, still yes.
<h2>Answer</h2>
1m/s
<h2>Explanation</h2>
Given that:
<em>Mass of first blob = 2kg = m1</em>
<em>Velocity of blob = 4m/s = v1</em>
<em>Mass of second blob = 6kg = m2</em>
<em>Velocity of blob = 0m/s = v2</em>
<em />
To find:
<em>Final velocity = Vf</em>
<em />
<em>This question is of inelastic collision which is any collision between objects in which some energy is lost.</em>
<em />
<h3>Formula to be use:</h3><h2>(m1*v1) + (m2*V2) = Vf(m1 + m2)</h2>
(2*4) + (6*0) = Vf(2+6)
8 + 0 = Vf(8)
8 = Vf(8)
Vf = 1 m/s
So the speed of two blobs immediately after colliding = 1 m/s
