Question

An object takes 10 seconds to reach the ground from a height of 50 metres on a planet. Calculate the value of 'g' on that planet. The value of 'g' will be ________. *

Answer 1

Given :

• An object falls from a height, h = 50 m
• Initial velocity of object, u = 0      
• Time taken by object to reach Ground, t = 10 s

To find :

• Value of acceleration due to gravity on Planet, g = ?

Formulae required :

• Second equation of motion

    s = u t + 1/2 a t²

[ where s is distance covered, u is initial velocity, a is acceleration due to gravity and t is time taken ]

Solution :

In the given condition acceleration is equal to g ; so,

Using second equation of motion

→ s = u t + 1/2 g t²

→ 50 = ( 0 ) ( 10 ) + 1/2 ( g ) ( 10 )²

→ 50 = 1/2 ( g ) ( 100 )

→ 50 = 50 g

→ g = 50 / 50

→ g = 1 m/s²

therefore,

• Acceleration due to gravity on the Planet is 1 m/s².

Three equation of motion :

• First equation of motion

     v = u + a t

• Second equation of motion

     s = u t + 1/2 a t²

• Third equation of motion

     2 a s = v² - u²

[ where s is distance covered, u is initial velocity, a is acceleration due to gravity and t is time taken and v is final velocity of body ]

Answer 2

Answer:

1 m/s²

Explanation:

An object takes 10 seconds to reach the ground from a height of 50 metres on a planet.

From above we have time is 10 sec, initial velocity is 0 m/s and height is 50 m.

Using the second equation of motion,

s = ut + 1/2 gt² [ a = g ]

Substitute the values,

→ 50 = 0(10) + 1/2 × g × (10)²

→ 50 = 0 + g/2 × 100

→ 50 = 50g

Divide by 50 on both sides,

→ 50/50 = 50g/50

→ 1 = g

Hence, the value of g will be 1 m/s².