SecC LA XIV — task. Science Test Space, Class 7.

Section C: Give a long answer to the question given below.

A ball is gently dropped from a height of 20 \(m\). If its velocity increases uniformly at the rate of 10

m s^{- 2}

, with

a. What velocity will it strike the ground?

b. After what time will it strike the ground?

Solution:

From the data given,

Acceleration (\(a\)) \(=\) 10 \(\)

m s^{- 2}

Distance travelled by the ball (\(s\)) \(=\) 20 \(m\)

Initial velocity of the boat (\(u\)) \(=\) \(0\) \(m\)\(/\)\(s\) (Since it's start from the rest state)

From the Equation of motion - III, We know that,

i^{i} = i^{i} + i i i

Substituting the given values of \(u\), \(a\) and \(s\) in the above equation, we get

Velocity \(=\)

m s^{- 1}

From the Equation of motion - I, We know that,

i = i + i i

Substituting the known values in the above equation, we get

Time \(=\) \(s\)

Did you find an error?

14. SecC LA XIV