Question

A body accelerates from rest to speed of 36kmh^-1 in 20 s. The acceleration of the car in ms^-2 is. a)0.5 b)1.8 c)5 b)18

Answer 1

ɢɪᴠᴇɴ :-

• Initial velocity (u) = 0
• Final velocity (v) = 36 km/h × 5/18 = 10m/s
• Time taken (t) = 20s

Tᴏ ғɪɴᴅ :-

• Acceleration (a)

sᴏʟᴜᴛɪᴏɴ :-

We know that,

$\implies \sf \: Acceleration(a) \: = \frac{Final \: Velocity(v) \: - Initial \: Velocity(u)}{Time \: Taken(t)} \\ \\ \implies \sf \: a = \frac{v - u}{t}$

Put the above given values in it, we get,

$\implies \: \sf a = \frac{10 - 0}{20} \\ \\ \implies \: \sf a = \frac{10}{20} \\ \\ \implies \:\sf a = 0.5m {s}^{ - 2}$

Hence,

• Acceleration = 0.5 m/s²

Hence,

• Option (a) 0.5 m/s² is correct

Answer 2

Answer:

Explanation:

Solution,

Here, we have

Initial velocity of body, u = 0 (As starts from rest)

Final velocity of body, v = 36 km/h = 36 × 5/18 = 10 m/s

Time taken by body, t = 20 seconds

To Find,

Acceleration by body, a = ??

According to the 1st equation of motion,

we know that,

v = u + at

Putting all the values, we get

⇒ v = u + at

⇒ 10 = 0 + a × 20

⇒ 10 = 20a

⇒ 10/20 = a

⇒ 1/2 = a

⇒ a = 0.5 m/s²

Hence, The acceleration of the car in m/s is 0.5 m/s².