Question

A MotherCycle is travelling at a speed of 20 m/s and speeds up to 40 m/s in 10 s. Calculating Distance?

Answer 1

The above Question falls from 'Motion'

Given

• Initial Speed (u) = 20 m/s
• Final Speed (v) = 40 m/s
• Time (t) = 10 s

To Find

• Distance Travelled

Formula Used

• v = u + at

Solution

➱ 40 = 20 + a × 10

➱ 40 = 20 + 10a

➱ 40 - 20 = 10a

➱ 20 = 10a

➱ 10a = 20

➱ a = 20/10

➱ a = 2

Therefore, the acceleration is 2 m/s²

Now, Calculating Distance Travelled

v² - u² = 2as

➱ (40)² - (20)² = 2 × 2 × s

➱ 1600 - 400 = 4s

➱ 1200 = 4s

➱ 4s = 1200

➱ s = 1200/4

➱ 300 m

Therefore, Distance Travelled is 300m

Additional Information

• SI unit of Acceleration is m/s²
• SI unit of Time is s
• SI unit of Speed = m/s
• The Speed that the body gains at it's start is known as Initial Speed & is denoted by u.
• The Speed that the body gains after it's start is said to be Final Speed & is denoted by v

Three Equations of Motion

• v = u + at
• v² - u² = 2as
• S = ut + ½at²

Answer 2

Given :

• Initial velocity (u) = 20m/s
• Final velocity (v) = 40m/s
• Time taken (t) = 10s

Find out :

• Distance travelled by motorcycle (s)

Solution :

According to the first equation of motion

➟ v = u + at

➟ 40 = 20 + a*10

➟ 40 - 20 = 10a

➟ 20 = 10a

➟ a = 20/10 = 2m/s²

Hence

• Acceleration of motorcycle is 2m/s²

Now, according to the third equation of motion

➟ v² = u² + 2as

➟ (40)² = (20)² + 2*2*s

➟ 1600 = 400 + 4s

➟ 1600 - 400 = 4s

➟ 1200 = 4s

➟ s = 1200/4 = 300m

Hence,

• Distance travelled by motorcycle is 300m

Additional Information

• s = ut + ½ at² {second equation of motion}
• The rate of change in velocity is known as acceleration
• S.I unit of acceleration is m/s²
• Acceleration is vector quantity {magnitude and direction}