Question

mass of a motorcycle along with the passenger in 900 kg. calculate the force excreted by the brakes on the motorcar which is moving with the velocity of 108km/h and takes 5s to stop after the application of brakes ​

Answer 1

Given :

Mass of object = 900kg

Initial velocity = 108km/hr

Final velocity = zero

Time interval = 5s

To Find :

Force exerted by the brakes.

Solution :

❖ First of all we need to convert unit of velocity from km/hr to m/s.

We know that, 1 km/hr = 5/18 m/s

∴ 108 km/hr = 108 × 5/18 = 30m/s

As per newton's second law of motion, force is defined as the rate of change of linear momentum$.$

Mathematically, F = m(v - u) / dt

• F denotes mass
• v denotes final velocity
• u denotes initial velocity
• dt denotes time

By substituting the given values;

➙ F = 900(0 - 30) / 5

➙ F = -27000/5

➙ F = -5400 N

[Negative sign shows retardation of motorcycle]

Answer 2

$\huge\colorbox{yellow}{Áηѕωєя࿐❤}$

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Given :

Mass of object = 900kg

Initial velocity = 108km/hr

Final velocity = zero

Time interval = 5s

To Find :

Force exerted by the brakes.

Solution :

❖ First of all we need to convert unit of velocity from km/hr to m/s.

We know that, 1 km/hr = 5/18 m/s

∴ 108 km/hr = 108 × 5/18 = 30m/s

As per newton's second law of motion, force is defined as the rate of change of linear momentum..

Mathematically, F = m(v - u) / dt

• F denotes mass
• v denotes final velocity
• u denotes initial velocity
• dt denotes time

By substituting the given values;

➙ F = 900(0 - 30) / 5

➙ F = -27000/5

➙ F = -5400 N

[Negative sign shows retardation of motorcycle]

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Hope it helps :)