Answer:
A. can never be efficient due to friction
Dependent / Response Variable: factor or condition in a experiment that changes as a result of the independent variable; often called the responding variable. ... Constant: factors or conditions in an experiment that are kept the same in as trials of the experiment. Control: a set up without the variable being tested.
Answer:
1) 
2) 
Explanation:
Given:
- mass of heavier student,
- mass of lighter student,
- velocity of the heavier student after the mutual push,
1)
Since they push each other and we are neglecting any friction that means we can consider this as a perfectly elastic collision. So the momentum of the two bodies will be equal and in opposite direction.
Since momentum is a vector quantity so the total momentum of the system as a whole will be zero.
2)
<u>From the condition of elastic collision:</u>
Answer:
Change in momentum is 
Solution:
The momentum of any body is the product of its mass and the velocity associated with the body and is generally given by:
Now, as per the question:
Mass of the car, M = 1500 kg
The velocity in the east direction, 
The velocity in the north direction, 
Now, the momentum of the car in the east direction:
Now, the momentum of the car in the north direction:
Change in momentum is given by:
Now,
(Since, 
)
Verrrry interesting !
The curves are identical. That means that at every instant of time, the ball's horizontal and vertical displacement are equal.
That means that however high off the floor it is, it's exactly the same distance from the wall !
The ball is moving along a 45° diagonal path. It's like one of those contraptions with a ball connected to a wooden paddle by a rubber band. Any direction you hit the ball with the paddle, it goes out in that direction, and then it comes right back to the paddle.
-- This ball begins at (0,0) ... where the wall meets the floor.
-- For the first 3 seconds, it goes straight out at a 45° angle. However far from the wall it is, it's exactly the same distance up from the floor.
-- After 3 seconds, it's 4 meters from the wall and 4 meters above the floor. It's at the point (3, 4) on both graphs.
-- Then it stops going out, and comes back.
-- After 6 seconds, it's back at the point (0, 0) again, where the wall meets the floor.
