Question

A ball is thrown up and attains a maximum height of 19,6 m. it's speed was:
(A) 9.8 ms
(B) 44.3 ms1
(C) 19.6 ms1
(D) 98 ms
The value of g at pole is:
(A) greater than the value at the equator
(B) less than the value at the equator
(C) equal to the value of the equator
(D) none of these
​

Answer 1

Answer:

1) (c)

2) (a)

Explanation:

1) $H_{max} = \frac{u^{2}}{2g}$

⇒ u² = 2gH

⇒ u² = 2 × 9.8 × 19.6

⇒ u² = 2 × 2 × 9.8 × 9.8

⇒ u = 2 × 9.8

∴ u = 19.6 m/s (c)

Hence (c) is the correct answer.

2) The centrifugal force due to the spinning of the Earth is maximum at the equator and minimum at the poles. Hence, the acceleration due to gravity (g) is minimum at the equator and maximum at the poles.

Hence (a) is the correct answer.

Thanks !