Question

please tell me the answer
I cannot understand physics in online classes.. ​

Answer 1

ANSWER :

Final velocity of the body is 80 m/s.

Explanation:

Given :

• u = 0 m/s ( body is at rest )
• a = 4 m/s^2
• s = 800 m
• v = ?

By using third kinematical equation :

• $\sf v^2 - u^2 = 2as$

we get,

$\sf v^2 - 0^2 = 2 (4)(800)$

$\sf\implies v^2 = 2\times 3200$

$\sf\implies v^2 = 6400$

$\sf\implies v =\sqrt{6400}$

$\sf\therefore v = 80\:m/s$

Hence,

the final velocity of the object is 80 m/s.

$\rule{200}2$

Answer 2

❍According to Question

✰Given:-

➠ Initial velocity (u) = 0m/s

➠ Acceleration (a) =4m/s²

➠ Distance (s) =800m

✰To Find:-

⋄ Final velocity ???

✰Solution :-

By using third equation of motion

$v {}^{2} = u {}^{2} + 2as \\ \\ v {}^{2} = 0 {}^{2} + 2 \times 4 \times 800 \\ \\ v {}^{2} = 6400 \\ \\ v = \sqrt{6400} \\ \\ v = 80ms {}^{ - 1}$

∴The final velocity of body is 80m/s.