Question

Train moves from rest to a speed of 80 m/s in 40 seconds. What is the magnitude of its acceleration?​

Answer 1

Answer:

2 m/s²

Explanation:

As per the provided information in the gi en question, we have :

• Initial velocity (u) = 0 m/s (As it starts from rest)
• Final velocity (v) = 80 m/s
• Time taken (t) = 40 seconds

We are asked to calculate the magnitude of its acceleration.

By using the acceleration formula,

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

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

$\longmapsto \rm {a = \Bigg (\dfrac{80-0}{40} \Bigg ) \; ms^{-2}}$

$\longmapsto \rm {a = \Bigg (\dfrac{80}{40} \Bigg ) \; ms^{-2}}$

$\longmapsto \bf {a = 2 \; ms^{-2}}$

∴ Acceleration of the car is 2 m/s².

*Note : We can also solve this question by using the first equation of motion that is v = u + at.

More Information :

• Acceleration is the rate of change in velocity with time.
• It is a vector quantity.
• Its SI unit is m/s².
• Negative acceleration is called retardation.
• Retardation is also called deceleration.

Answer 2

★ Required answer ★

• Acceleration of train is 2m/s².

★ Given:-

• ⇒ Initial velocity of train (u) = 0
• ⇒ Final velocity of train (v) = 80m/s
• ⇒ Time taken by train (T) = 40sec

★ To find:-

• Acceleration of the train?

★ Solution:-

• ⇒ V = u + at
• ⇒ 80 m/s = 0 + a × 40s
• ⇒ 80 m/s = 0 + 40a
• ⇒ 80 m/s = 40a
• ⇒ a = 80/40 m/s²
• ⇒ a = 8/4 m/s²
• ⇒ a = 2 m/s²

•°• Acceleration of train is 2m/s².