Question

a truck starts from rest and roll down a hill it travels a distance of 400m in 20s find its acceleration​

Answer 1

Answer:

2 m / sec²

Explanation:

Given :

Initial velocity ( u ) = 0 m / sec

Distance ( s ) = 400 m

Time ( t ) = 20 sec.

We have to tell acceleration :

Using second equation of motion :

s = u t + 1 / 2 a t²  [ u = o ]

2 s = a t²

Putting values now :

2 × 400 = a × 20 × 20

2 × 400 = 400 × a

a = 2 m / sec² .

Thus the acceleration of truck is 2 m / sec² .

Answer 2

$\huge{\mathfrak{\underline{\underline{\red{Answer :-}}}}}$

Acceleration(a) = 2 m/s²

$\large{\mathrm{\gray{\underline{Given:-}}}}$

Initial velocity(u) = 0 m/s

Distance(s) = 400 m

Time(t) = 20 s

$\large{\mathrm{\gray{\underline{To \: Find :-}}}}$

Acceleration (a)

$\large{\mathrm{\gray{\underline{Solution :-}}}}$

Using second equation of motion

$\large{\boxed{\boxed{s \: = \: ut + \frac{1}{2} at^{2}}}}$

____________[putting values]

⇒ 400 = 0(20) + 1/2 * a * (20)²

⇒ 400 * 2 = a * 400

⇒ 800 = a * 400

⇒ 800/400 = a

⇒ a = 2 m/s²

$\huge{\boxed{\boxed{a \: = \: 2m/s ^{2}}}}$

$\large{\mathrm{\gray{\underline{Points \:to \: remember :-}}}}$

• When any object starts from rest than initial velocity(u) is 0 m/s

• When any object comes in rest from motion then final velocity(v) is 0 m/s