Question

A car has a mass of 900kg . it accelerate from rest at a rate of 1.2m/s2 find the time taken to reach velocity of 30m/s

Answer 1

Given :

• Mass of car, m = 900 kg
• Initial velocity, u = 0 m/s [From rest]
• Acceleration, a = 1.2 m/s²
• Final velocity, v = 30 m/s

To calculate :

• The time taken to reach velocity of 30m/s.

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Solution :

By using the 1st equation of motion :

$\quad \star\; \underline{\boxed{\textbf{\textsf{v = u + at }}} }$

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

$\quad \twoheadrightarrow\sf {30 = 0 + 1.2t }$

$\quad \twoheadrightarrow\sf {30 = 1.2t }$

$\quad \twoheadrightarrow\sf {\dfrac{30}{1.2} = t }$

$\quad \twoheadrightarrow\sf {\cancel{\dfrac{300}{12}} = t }$

$\quad \twoheadrightarrow\underline{\boxed{\textbf{\textsf{25 \; s = t }}} }$

Therefore, the time taken to reach velocity of 30m/s is 25 seconds.

Answer 2

Answer:

Given :-

• A car has a mass of 900 kg.
• It's accelerates from rest at a rate of 1.2 m/s².

To Find :-

• What is the time taken to reach velocity of 30 m/s.

Formula Used :-

$\clubsuit$ First Equation Of Motion Formula :

$\bigstar \: \: \sf\boxed{\bold{\pink{v =\: u + at}}}\: \: \: \bigstar$

where,

• v = Final Velocity
• u = Initial Velocity
• a = Acceleration
• t = Time Taken

Solution :-

Given :

• Initial Velocity = 0 m/s
• Acceleration = 1.2 m/s²
• Final Velocity = 30 m/s

According to the question by using the formula we get,

$\implies \bf v =\: u + at$

$\implies \sf 30 =\: 0 + (1.2)t$

$\implies \sf 30 =\: 0 + 1.2t$

$\implies \sf 30 - 0 =\: 1.2t$

$\implies \sf 30 =\: 1.2t$

$\implies \sf \dfrac{30}{1.2} =\: t$

$\implies \sf 25 =\: t$

$\implies \sf\bold{\red{t =\: 25\: seconds}}$

$\small \sf\bold{\purple{\underline{\therefore\: The\: time\: taken\: to\: reach\: velocity\: is\: 25\: seconds\: .}}}$

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