Question

A particles is projected vertically upwards and it is at a height h after 2 secs and again after 10secs, the height h is a)196m b)98m c)9.8m d)19.6m

Answer 1

Answer:

Let u be the velocity of the projection and O be the point of projection. Let P be the point in the path of the particle such that OP=h. Then,

h=ut−

2

1

gt

2

⇒gt

2

−2ut+2h=0...(i)

Clearly, t

1

t

2

, are two roots of this equation.

∴t

1

t

2

=

g

2h

⇒h=

2

1

gt

1

t

2