Question

A car moving with 15m/s uniformly slows its velocity. It comes to a complete stop in 10s. What is the acceleration?

Answer 1

Answer:

The acceleration is –1.5 m/s².

Step-by-step explanation:

Given:

The car moving with speed = 15 m/s

Car travelled for = 10 seconds

To find:

Acceleration = ??

Solution :

$\boxed{\sf{Acceleration \: = \frac{(v - u)}{t}}}$

• u = 15 m/s
• v = 0 m/s
• t = 10 secs

$\sf{\longrightarrow} \: \ \dfrac{(0 - 15)}{10}$

$\sf{\longrightarrow} \: \dfrac{ - 15}{10}$

$\sf{\longrightarrow} \: - 1.5 \:$

Acceleration = –1.5 m/s²

Therefore, the acceleration is –1.5 m/s².

Answer 2

Given :

• A car is moving with a velocity of 15 m/s.

That means,

☛ Initial velocity (u) of the car is 15 m/s.

• It comes to stop in 10 s.

That means,

☛ Final velocity (v) of the car is 0 m/s.

☛ Time taken (t) = 10 s

To Find :

• Acceleration of the car.

Solution :

As we know that,

✳ To calculate acceleration, we use the equation of motion is given as

$\orange\bigstar\:\mid\:\bf\pink{v\:=\:u\:+\:at}\:\mid\:\green\bigstar$

➵ 0 = 15 + a × 10

➵ 10a = -15

➵ a = $\sf{\dfrac{-15}{10}}$

➵ a = $\sf{-\dfrac{3}{2}}$

➵ a = - 1.5 m/s²

[Note ➝ Here negative sign indicates that car is accelerated in the opposite direction, is called as deacceleration.]

∴ The acceleration of the car is 1.5 m/s².