Question

A particle starts moving with acceleration 2m/s distance travelled by it in 5th half second is: A1.25 m b 2.25 m c 6.25 m d 30.25 m

Answer 1

Given, 
Acceleration = 2m/s²
Intial velocity u = 0 m/s
Given time = 5th half second ⇒ 5x1/2 = 2.5s

By using, Sₓ = ut + (1/2)at²
                S₅ = (0)5 + (2)(2.5)²/2
                S₅ = 0+(2)(6.25)/2
                S₅ = 6.25m

So option c (6.25m) is correct.

Answer 2

Answer:

b)2.25m

Explanation

Distance travelled in the fifTH half second

=Distance traveled in 2.5 seconds-Distance travelled in 2 seconds

=

$(\frac{1}{2} \times {2.5}^{2} \times 2 )- ( \frac{1}{2} \times {2}^{2} \times 2 )$

$= 6.25 - 4$

$2.25$

So the answer is b)2.25 m and not 6.25 m because it is asked about the distance travelled in FIFTH half seconds not five half seconds.

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