Question

A bus running at a speed of 18 km/h is stopped in 2.5 seconds by applying brakes. Calculate the retardation produced. ​

Answer 1

Answer:

given: u = 18km/hr = 18*5/18 = 5 m/sec

v = 0, t = 2.5 sec

to find: a

formula used : v = u + at

=> 0 = 5 + a × 2.5

=> 2.5 a = -5

=> a = -5/2.5

=> a = - 2 m / sec²

retardation = - 2 m / sec²

Answer 2

☣ Qᴜᴇsᴛɪᴏɴ ☣

➥ A bus running at a speed of 18 km/h is stopped in 2.5 seconds by applying brakes. Calculate the retardation produced.

⛦ Aɴsᴡᴇʀ ⛦

➥ Retardation (a) = 2 m/s²

☄ Gɪᴠᴇɴ ☄

➤ Intial velocity (u) = 18 km/h

➤ Time (t) = 2.5 second

⚛ Tᴏ Fɪɴᴅ ⚛

➤ Retardation (a) = ?

$\rule{195}{3}$

• u denoted by intial velocity
• v denoted by final velocity
• t denoted by time
• a denoted by acceleration

$\rule{195}{3}$

⠀⠀⠀⠀⠀⠀

❏ According To Given Question

⠀⠀⠀⠀⠀⠀

↗ Retardation is negative acceleration it can be calculate the 1st equation of motion.

$\sf{ : \implies u = 18 \: km/h} \\ \\ \sf{ : \implies u = \frac{18000 \: m}{3600 \: sec} } \\ \\ : \sf{\implies \underline{ \boxed{ \green{ \bf{ u = 5 \: m/s}}}}}$

❊ As we know that the formula for finding the acceleration is ፦

$\displaystyle{\rm{ : \implies a = \frac{v - u}{t} }}$

⤵ On putting the given value in the formula, we get

$\sf{ : \implies a = \frac{ - 5 \: m/s}{2.5 \: s} } \\ \\ \sf{ : \implies a = - 2\: m/s} \\ \\ \sf{ : \implies \underline{ \boxed{ \purple{ \bf{ Retardation = 2 \: m/s} }}}}$