Question

A ship is moving at 60 km / h one second later it is moving at 58 km/ h what is its acceleration

Answer 1

Given :

Initial velocity of the ship : 60 km/hr

Final velocity of the ship : 58 km/hr

Time taken : 1 sec

To find :

The acceleration of the ship.

Solution :

Firstly we have to convert km/hr to m/s

we know that,

» 1km/hr = 5/18km/hr

» 60km/hr = 60 × 5/18 = 16.6 m/s

» 58km/hr = 58 × 5/18 = 16.1 m/s

Accerlation is the rate of change of velocity.

• It is a vector quantity having both magnitude as well as direction.
• SI unit of acceleration is metre per second square.

As we are provided with initial velocity, final velocity and time we can use first equation of kinematics that is,

v = u + at

• v denotes final velocity
• u denotes initial velocity
• a denotes acceleration
• t denotes time taken

by substituting all the given values in the formula,

➝ v = u + at

➝ 16.1 = 16.6 + a(1)

➝ a = 16.1 - 16.6

➝ a = - 0.5 m/s²

Thus, the acceleration of the ship is -0.5 m/s².

If the speed is decreasing with time then accerlation is negative. The negative accerlation is called deceleration or retardation.

Know more :

First equation of kinematics : v = u + at

Second equation of kinematics : s = ut + 1/2at²

Third equation of kinematics : v² - u² = 2as

Answer 2

Answer:-

• initial velocity=u=60km/h
• Final velocity=58km/h

Convert both into m/s

$\\ \sf\longmapsto 60\times \dfrac{5}{18}$

$\\ \sf\longmapsto 16.6m/s$

And

$\\ \sf\longmapsto 58\times \dfrac{5}{18}$

$\\ \sf\longmapsto 16.1m/s$

• Time=1s

According to 1st equation of motion

$\boxed{\sf v=u+at}$

$\\ \sf\longmapsto a=\dfrac{v-u}{t}$

$\\ \sf\longmapsto a=\dfrac{16.1-16.6}{1}$

$\\ \sf\longmapsto a=-0.5m/s^2$