Question

A stone is thrown in a vertically
upward direction with a velocity
of 5 ms-1. If the acceleration ofthe
stone during its motion is 10m s-2
in the downtoard direction, what
will be the height attained by the
stone and how much time will it
taice to reach there?​

Answer 1

Explanation:

ANSWER

Given, initial velocity, u=5ms

−1

Final velocity, v=0

Since, u is upward & a is downward, it is a retarded motion.

∴a=−10ms

−2

Height attained by stone, s=?

Time take to attain height, t=?

(i) Using the relation, v

2

−u

2

=2as, we have

s=v

2

−u

2

/2a

=(0)

2

−(5)

2

/2×(−10)=1.25m

(ii) Using the relation, v=u+at

0=5+(−10)t or

t=5/10=0.5s

Answer 2

Answer:

s=1.25m

t=1/2 min

Explanation:

u=5m/s

v=0

a=10m/s^2

v=u-at

or, 0=5-10t

or, 10t=5

or, t=1/2

s=ut+1/2at^2

or, s=5*1/2+1/2*(-10)*(1/2)^2

or, s=5/2-5/4

or, s=(10-5)/4

or, s=5/4

or, s=1.25

Hope this helps.....