Answer:
Energy lost due to friction is 22 J
Explanation:
Mass of the ball m = 4 kg
Initially velocity of ball v = 6 m/sec
So kinetic energy of the ball 
Now due to friction velocity decreases to 5 m/sec
Kinetic energy become
Therefore energy lost due to friction = 72 -50 = 22 J
Displacement only measure how far between the starting and ending point. In this case, Lisa walks around the block as a circle so the starting point is the same as the ending point. Thus, displacement is 0mile.
On the other hand, distance measures exactly how far she walks. In this case, the distance is 1 mile, same as the perimeter of the block.
This attraction occurs from adhesion, also known as adsorption <span />
The image of the object is 8cm to the left of the lens (D)
<h3>
</h3>
What is the image of an object?
The image of an object is said to be the location where light rays from that object intersect with a mirror by reflection.
It is calculated thus:
1÷v = 1÷f - 1÷u
<h3>How to calculate the image of an object</h3>
From the formula
1÷v = 1÷f - 1÷u
<h3>
Where </h3>
V = image distance fromthe object
U = object
f = focal length
Substitute the values
1÷v = 1÷8 - 1÷ 4
1÷v = - 1÷8
Make v the subject of formula
v = -8cm
Therefore, the image of the object is 8cm to the left of the lens (D)
Learn more on focal length here:
brainly.com/question/25779311
#SPJ1
Answer:
The friction force is 250 N
Explanation:
The desk is moving at constant velocity. This means that its acceleration is zero: a = 0. Newton's second law states that the resultant of the forces acting on the desk is equal to the product between mass (m) and acceleration (a):
In this case, we know that the acceleration is zero: a = 0, so also the resultant of the forces must be zero:
(1)
We are only interested in the forces acting along the horizontal direction, since it is the direction of motion. There are two forces acting in this direction:
- the pull, forward, F = 250 N
- the friction force, backward, 
Given (1), we have
So the force of friction must be equal to the pull:
