Answer:
Work done, W = 6 J
Explanation:
It is given that,
Force of gravity acting on the book, weight of the book is 15 N
We need to find the work done in lifting the book straight up for a distance of 0.4 meters.
The weight of the book is acting in downward direction and the book is lifted straight up, it means angle between them is 180 degrees. Work done is given by :

So, the magnitude of work done in lifting the book is 6 joules.
Newton's 2nd law of motion: Force = (mass) x (acceleration)
If you want to move a 7-kg object with an acceleration of 4 m/s²,
then you will need to push it with (7 x 4) = 28 newtons of force.
Answer:
The direction is due south
Explanation:
From the question we are told that
The energy of the electron is 
The earths magnetic field is 
Generally the force on the electron is perpendicular to the velocity of the elecrton and the magnetic field and this is mathematically reresented as

On the first uploaded image is an illustration of the movement of the electron
Looking at the diagram we can see that in terms of direction the magnetic force is


generally i cross k = -j
so the equation above becomes


This show that the direction is towards the south
Answer:(a)9.685 mm
(b)4.184 mm
Explanation:
Given
Wavelength of light 
Width of slit(b)=0.210
(a)Width of central maximum located 1.80m from slit


=9.685 mm
(b)Width of the first order bright fringe


