When a force is applied to the box , this will cause an acceleration to the box.
(force =mass×acceleration)
So the box has a constant acceleration and a changing velocity.
The velocity is 4374.45 m/s.
I got the answer by using v=d/t.
20,000meters / 25min= 4,374.45 m/s.
Solution:
In this question we have given,
initial velocity,u = 0
final velocity, v = 1m/s
displacement =.5mm (Because 1mm=.001m)
We have to find
1.acceleration
2. Time
1. we know third equation of motion is given as,
............(1)
Put values of v,u and s in equation (1)
![[tex]s=1^{2} = 0^{2} +2X.0005Xa\\1= .001a\\therefore, a = 1/.001\\ a= 1000m/s^{2}](https://tex.z-dn.net/?f=%5Btex%5Ds%3D1%5E%7B2%7D%20%3D%200%5E%7B2%7D%20%2B2X.0005Xa%5C%5C1%3D%20.001a%5C%5Ctherefore%2C%20a%20%3D%201%2F.001%5C%5C%20a%3D%201000m%2Fs%5E%7B2%7D)
2. We know First equation of motion is given as
......................(2)
put values of v, u and a in equation(2)

Can be made out of ; sand, rocks or soil if the current is not expected to be rough.
Answer:
Focal length of the eye-lens is 2.0 cm
Explanation:
Given:
An eye-lens system which will follow converging lens (convex lens) sign conventions and knowing that lens-retina distance is the image distance.
Object distance,
= 
Image distance,
=
cm
We have to find the focal length.
Lets say that the focal length is
.
Lens Formula:
⇒ 
Sign-convention:
We will follow the Cartesian coordinate,placing the lens at the origin of the plane, optical center is at
now as the object will be towards negative x-axis so it is negative others are on the right side of the origin so they are positive.
Using the lens formula:
⇒ 
⇒
⇒
<em>...as </em>
a<em>nd there is no </em>
<em> so it is zero only.</em>
⇒
cm
So the focal length is 2.0 cm with two significant figures.