KINEMATICS graph mCqS help....

[hassam]

 

[hassam]

come on....plx solve these questions for me.i need expalanation

 

[Xenon]

For question 1(first question, second attachment):
Ek= kinetic energy
s= displacement

Ek= (1/2)mv^2
=(1/2)m(u^2+ 2as)
=(mu^2/2) + (mas)
Since the object starts from rest, u=0 and a is constant (so is m)
therefore, Ek= mas
The graph is a straight line through the origin

Ans: C

P.S: Correct me if I am wrong.

 

[hassam]

thnxx i got the whole point nearly..bt one thing i wanna ask dat k.e=m.a.s is the quation of the straight line ryt with gradient m.a . means times

 

[hassam]

 

[hassam]

from the above pic u cn see that ans to q2 in 2nd pic was D

 

[Xenon]

gradient m.a . means times

Did u mean,
mass (m) x acceleration (a) = time

if so, then no of course:
unit of mass = kg
acceleration = m/s^2
m x a = kg m/s^2 = N (force)

since a is constant, f is also constant

 

[hassam]

no no i meant that the . (dot) represented multiplicaltion or times

 

[Xenon]

yeah, ....i think so.