Manipal Entrance Test 2014 Physics Paper

In non-uniform circular motion two forces will work on a particle Fc and Ft
So, the net force FNet=√Fc2+Ft2 .....(i)
Centripetal force Fc=

mv2

R

=

2as2

R

....(ii)
[given

1

2

mv2=as2 given ]
Again from

1

2

mv2=as2
⇒ v2=

2as2

m

⇒ v=s√

2a

m

Tangential acceleration at=

dv

dt

=

dv

ds

.

ds

dt

⇒ at=

d

ds

[s√

2a

m

].v
at=v√

2a

m

=s√

2a

m

√

2a

m

=

2as

m

and Ft=mat=2as ...(iii)
Now, on substituting value of Fc and Ft in Eq.(i), we get
∴ FNet=√(

2as2

R

)2+(2as)2 =2as[1+

s2

R2

]

1

2