Question

physics 9th class all derivatives easy method solving and proving​

Answer 1

derivation of v=u+at

consider a body is moving with uniform acceleartion in a straight line

Let,

u=initial velocity

v=velocity

s=distance travelled

t=time period

and a=uniform acceleration

as we know that ,a=(v-u)/t

at=(v-u)

at+u=v  

Answer 2

this are of motion chapter

Work and energy

P. E=force×displacement

mg×h

mgh

p. e(potential energy)

K. E=1/2mv²

derivation

in this motion one equation will be used v²-u²=2as

this gives

1/2m(v²-u²)

u=0

W=1/2mv²

we know that work done is equal to the change in the kinetic energy of an object u=0 then the work done will be 1/2mv²

E. k=1/2mv²