Question

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

Answer 1

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:

Max height attained is 8.75m

And Time required to reach there is 0.5 s

Step-by-step explanation:

Given,

u = 5 m/s

a = -10 m/s^2

v = 0 (For max height attained)

Formulae,

v = u + at

s = ut + 1/2at^2

0 = 5 + (-10)t

-5 = (-10)t

t = 0.5 s

Therefore,

s = (5)(2) + (1/2)(-10)(0.5)^2

s = 10 + (-1.25)

s = 8.75