A 100kg crate slides along a floor with a starting velocity of 21 m/s. If the force due to friction is 8N, then, it will take 262.5 s for the box to come to rest.
We'll begin by calculating the declaration of the box. This can be obtained as follow:
Force (F) = –8 N (opposition)
Mass (m) = 100 Kg
<h3>Deceleration (a) =? </h3>
<h3>F = ma</h3>
–8 = 100 × a
Divide both side by 1000
<h3>a = –0.08 ms¯²</h3>
Therefore, the deceleration of the box is –0.08 ms¯²
Finally, we shall determine the time taken for the box to come to rest. This can be obtained as follow:
Deceleration (a) = –0.08 ms¯²
Initial velocity (u) = 21 ms¯¹
Final velocity (v) = 0 ms¯¹
<h3>Time (t) =.? </h3>
<h3>v = u + at</h3>
0 = 21 + (–0.08×t)
0 = 21 – 0.08t
Collect like terms
0 – 21 = –0.08t
–21 = –0.08t
Divide both side by –0.08
<h3>t = 262.5 s</h3>
Therefore, it will take 262.5 s for the box to come to rest.
Learn more: brainly.com/question/14446351
Answer: A.AB
Explanation:
This Velocity vs Time graph shows the acceleration of a body or object, since acceleration is the variation of velocity in time.
As we can see in the attached image, the graph can be divided in four segments:
OA: In this segment the acceleration is changing at a uniform rate. In addition we can see it has a positive slope, hence we are dealing with a positive uniform acceleration.
AB: In this segment the acceleration is changing at a nonuniform rate, since in this part it is not possible to calculate the slope. However if this were uniform, the slope woul be positive. This means the <u>acceleration is nonuniform and positive.</u>
BC: In this segment the acceleration is changing at a nonuniform rate, since in this part it is not possible to calculate the slope. However if this were uniform, the slope woul be negative. This means the acceleration is nonuniform and negative.
CD: In this segment the acceleration is changing at a uniform rate. In addition we can see it has a negative slope, hence we are dealing with a negative uniform acceleration.
From all these segments, the only one that fulfils the nonuniform positive acceleration condition is option A:
Segment AB
If a force always acts perpendicular to an object's direction of motion, that force cannot change the object's kinetic energy. It is a true statement .
Kinetic energy is the energy that an object possesses due to its motion. It is basically the energy of mass in motion. Kinetic energy can never be negative and it is a scalar quantity i.e. it provides only the magnitude and not the direction.
According to law of conservation of mechanical energy change in potential energy is equal and opposite to the change in the kinetic energy.
According to the principle of conservation of mechanical energy, The total mechanical energy of a system is conserved i.e., the energy can neither be created nor be destroyed; it can only be internally converted from one form to another if the forces doing work on the system are conservative in nature.
since, potential energy is stored in the form of work done
Work done = Fs cos (theta)
If force always acts perpendicular to an object's direction of motion
theta = 90 °
cos (90 ) = 0
Work done = 0
since , there is no work done , hence kinetic energy will not change
To learn more about kinetic energy here
brainly.com/question/12669551
#SPJ4
Explanation:
<em>"The accuracy of a potentiometer can be increased by decreasing the potential gradient across the potentiometer wire, and this can be achieved by increasing the length"</em>
<em />
<u>The factors that are affecting/limiting the accuracy of the potentiometer are:
</u>
-
The specific resistance of the material of the potentiometer wire.
- The potential gradient
- The current passing through the potentiometer wire.
- Area of a cross-section of the wire
- Internal temperature.
<u>The objective of reversing the terminals of the cell</u>
If the jockey of the potentiometer is pressed for a long time, joule heating sets in, so that reversing the terminals of the potentiometer will prevent the resistance due to joule heat from being added to the measured resistance, ultimately preventing unwanted resistance
