CBSE-XI-Physics
05: Newton's Laws of Motion
- #1A block of mass 2 kg placed on a long frictionless horizontal table is pulled horizontally by a constant force F. It is found to move 10 m in the first seconds. Find the magnitude of F.Ans : Given:
Mass of the block, m = 2 kg,
Distance covered, S = 10 m and initial velocity, u = 0
Let a be the acceleration of the block.
Using, `` \,\mathrm{\,S \,}=ut+\frac{1}{2}a{t}^{2}``, we get:
`` 10=\frac{1}{2}a\left({2}^{2}\right)``
`` \Rightarrow 10=2a``
`` \Rightarrow a=5\,\mathrm{\,m \,}/{\,\mathrm{\,s \,}}^{2}``
∴ Force, F = ma = 2 × 5 = 10 N
Page No 79: