Question

an object moving at 36km/h reduces its speed to 18km in 2 seconds if the mass is 20kg find the average force​

Answer 1

Given :

Initial velocity = 36km/hr = 10m/s

Final velocity = 18km/hr = 5m/s

Time interval = 2s

Mass of object = 20kg

To Find :

Average force acts on the object.

Solution :

❖ First of all we need to calculate acceleration of the object$.$

• It is defined as the rate of change of velocity.
• Acceleration is a vector quantity having both magnitude as well as direction.
• SI unit : m/s²

Formula : a = (v - u) / t

» v denotes final velocity

» u denotes initial velocity

» a denotes acceleration

» t denotes time

By substituting the given values;

➙ a = (5 - 10) / 2

➙ a = -5/2

➙ a = -2.5 m/s²

Negative sign shows retardation.

♦ Force acts on the object :

➛ F = m a

➛ F = 20 × (-2.5)

➛ F = -50N

➛ Average force, |F| = 50N

Answer 2

$\huge{\boxed{\bold{Question}}}$

an object moving at 36km/h reduces its speed to 18km in 2 seconds if the mass is 20kg find the average force

Given :

Initial velocity = 36km/hr = 10m/s

Final velocity = 18km/hr = 5m/s

Time interval = 2s

Mass of object = 20kg

To Find :

Average force acts on the object.

Solution :

❖ First of all we need to calculate acceleration of the object..

It is defined as the rate of change of velocity.

Acceleration is a vector quantity having both magnitude as well as direction.

SI unit : m/s²

Formula : a = (v - u) / t

» v denotes final velocity

» u denotes initial velocity

» a denotes acceleration

» t denotes time

By substituting the given values;

➙ a = (5 - 10) / 2

➙ a = -5/2

➙ a = -2.5 m/s²

Negative sign shows retardation.

♦ Force acts on the object :

➛ F = m a

➛ F = 20 × (-2.5)

➛ F = -50N

➛ Average force, |F| = 50N