Question

A Scooteristtravelling with a velocity
of 20km/hr accelerate with an acceleration
of 0.10 ms ^-2 After what time will
it velocity be 38 km/hr​

Answer 1

u = 5.5 m/s (20 km/h)

v = 10.5 (38 km/h)

a = 0.10 m/s

as we know

a= v- u/t

this could be written as

t= v - u/ a

= 10.5 - 5.5/0.10

= 5/0.10

= 50 s

Answer 2

Gɪᴠᴇɴ

Initial velocity = 20 km/h

Acceleration = 0.1 m/s²

Final velocity = 38 km/h

Tᴏ ꜰɪɴᴅ

Time taken to attain final velocity

Sᴏʟᴜᴛɪᴏɴ ❶ 

Here, Initial velocity = 20 km/h

⇒ u = 20 × (5/18) m/s

⇒ u = 5.56 m/s

Again, final velocity = 38 km/h

⇒ v = 38 × (5/18) m/s

⇒ v = 10.56 m/s

We know that,

⇒ v = u + at

⇒ 10.56 = 5.56 + (0.1t)

⇒ 10.56 - 5.56 = 0.1t

⇒ 5 = 0.1t

⇒ t = 5/0.1

⇒ t = 50 s

Tʜᴇʀᴇꜰᴏʀᴇ,

Time taken to attain that velocity is 50 seconds.

Sᴏᴍᴇ ᴍᴏʀᴇ ꜰᴏʀᴍᴜʟᴀꜱ :

⇾ a = (v - u)/t

⇾ v² = u² + 2as

⇾ s = ut + ½at²