an object moving with the speed of 40 km/ h it stop after 30 minutes. find the acceleration of object
Answers
Given :
Initial velocity = 40 km/h
Final velocity = 0 km/h
Time taken = 30 min
To find :
The acceleration of the object.
Solution :
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 motion that is,
- v = u + at
here, v denotes initial velocity, u denotes final velocity, a denotes acceleration and t denotes time taken.
By substituting all the given values in the formula,
➝ v = u + at
➝ 0 = 40 + a(30)
➝ -40 = a(30)
➝ a = -40/30
➝ a = - 1.3 m/s²
Thus, the acceleration of the object is -1.3 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