Question

10. A body is thrown vertically upwards. If it travels
equal distances in 4th and 7th seconds of motion,
then the maximum height attained by the body is
(1) 125 m
(2) 100 m
(3) 50 m
(4) 75 m​

Answer 1

Answer:

use g(n-1/2) formula and equqte them

Answer 2

Answer:

125m

Explanation:

distance travelled in 4 seconds

h4 = u - g/2( 2t - 1)

h4 = u - g/2 (2×4 -1)

h4 = u - 7g/2 ----(1)

similarly, distance travelled by the body in 7 seconds

h7 = u - g/2(2×7 -1) = u -13g/2 --(2)

So h4 = - h7

u - 7g/2 = - ( u - 13g/2)

u - 7g/2 = -u + 13g/2

2u = 10g => u = 5g

maximum height attained by the body

= u^2/2g = (5g)^2/2g

= 25g/2 = 25 × 10/2 = 125 m