Question

a moving train is brought to test in 20 sec by applying brakes.Find the initial velocity if the retardation due to brakes is 2 metre per second square​

Answer 1

CORRECT QUESTION :-

★ A moving train is brought to rest in 20 seconds by applying brakes . Find the initial velocity is the retardation due to break is 2 m/s².

GIVEN :-

• Acceleration , a = -2 m/s²
• Final velocity , v = 0 m/s [ Breaks are applied ]
• Time , t = 20 sec

TO FIND :-

• The initial velocity , u.

SOLUTION :-

★ By using 1st equation of motion ★

→ v = u + at

• v = final velocity.
• u = initial velocity.
• a = acceleration.
• t = time taken.

→ 0 = u + (-2) × 20

→ 0 = u - 40

→ u = 40 + 0

→ u = 40

Hence the required initial velocity is 40 m/s.

Answer 2

Answer:

✡ Question ✡

⬛ A moving train is brought to test in 20 sec by applying brakes. Find the initial velocity if the retardation due to brakes is 2 m/s².

✡ Given ✡

⬛ Acceleration (a) = 2 m/s²

⬛ Velocity (v) = 0 m/s

⬛ Time (t) = 20 sec

✡ To Find ✡

⬛ Initial Velocity = ?

✡ Formula Used ✡

▶ 1st of equation of motion :-

✴ $\huge \bold{ \underline{ \mathbb{ \blue{v = u + at}}}}$ ✴

✡ Solution ✡

According to the question by using formula we get,

⭐ v = u + at ⭐

=> 0 = u + (2) × 20

=> 0 = u + 40

=> u = 40 + 0

=> u = $\</em></strong><strong><em>l</em></strong><strong><em>a</em></strong><strong><em>r</em></strong><strong><em>g</em></strong><strong><em>e</em></strong><strong><em> \bold{ \underline{ \mathbb{ \blue{</em></strong><strong><em>4</em></strong><strong><em>0</em></strong><strong><em>}}}}$

∴ The initial velocity is $\large{\green{\underline{\tt{</u><u>4</u><u>0</u><u>\</u><u>:</u><u> </u><u>m</u><u>/</u><u>s</u><u>}}}}$

Explanation:

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