Question

a small sphere is projected with a velocity of 3 ms -1 in a direction 60 degrees from the horizontal y axis on the smooth inclined plane. the motion of sphere takes place in x y plane. calculate the magnitude v of its velocity after 2 seconds.

Answer 1

Answer:1.5ms-1

The motion of the sphere takes place in a plane ; the x− and y− components of its acceleration are A

x=−gsin30 o ,a y

=0.The x−and y− components of the sphere's velocity at time t=2s are

V

x

=v

0x

−a

x

t=3sin60

o

−gsin30

o

×2=0.1ms

−1

V

y

=vcos

60

o

=constant=1.5ms

−1

so the magnitude of sphere's velocity is

∣

v

ˉ

∣=

v

x

2

+v

y

2

=

(0.1)

2

+(1.5)

2

=1.5ms

−1