Laws of Motion — Question 12

As we know,

S = ut + ($\dfrac{1}{2}$) at²

Given,

m = 500 g

Converting g to kg,

1000 g = 1 kg

500 g = ($\dfrac{1}{1000}$) x 500 kg

100 g = 0.5 Kg

Hence,

m = 0.5 Kg

u = 0

s = 4 m

t = 2 s

Substituting the values in the formula above we get,

$4 = (0 \times 2) + (\dfrac{1}{2} \times \text a \times 2^2) \\[0.5em] 4 = 0 + (\dfrac{1}{2} \times \text a \times 4) \\[0.5em] 4 = 2\text a \\[0.5em] \Rightarrow \text a = \dfrac{4}{2} \\[0.5em] \Rightarrow \text a = 2\ \text {m s}^{-2} \\[0.5em]$

Hence,

a = 2 m s ^-2

Now,

Force (f) = mass (m) x acceleration (a)

Substituting the values in the formula above we get,

$\text F = 0.5 \times 2 \\[0.5em] \Rightarrow \text F = 1\ \text N \\[0.5em]$

Hence,

Magnitude of force = 1 N