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In this question ii and jj are horizontal unit vectors. A particle PP of mass 2kg2\,\text{kg} moves under the action of two forces, (pi+qj)N(p i + q j)\,\text{N} and (2qi+pj)N(2q i + p j)\,\text{N}, where pp and qq are constants. Given that the acceleration of PP is (ij)ms2(i - j)\,\text{ms}^{-2} (a) find the value of pp and the value of qq.

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Q. In this question ii and jj are horizontal unit vectors. A particle PP of mass 2kg2\,\text{kg} moves under the action of two forces, (pi+qj)N(p i + q j)\,\text{N} and (2qi+pj)N(2q i + p j)\,\text{N}, where pp and qq are constants. Given that the acceleration of PP is (ij)ms2(i - j)\,\text{ms}^{-2} (a) find the value of pp and the value of qq.
  1. Addition of Forces: First, let's add the two forces together to get the total force acting on the particle PP.(p+iq)N+(2q+ip)N=(p+2q)i+(q+p)j(p+iq)\mathbf{N} + (2q+ip)\mathbf{N} = (p+2q)\mathbf{i} + (q+p)\mathbf{j}
  2. Newton's Second Law: Now, according to Newton's second law, Force=mass×acceleration\text{Force} = \text{mass} \times \text{acceleration}. So, the total force should equal the mass of the particle times its acceleration. Let's write that down: (p+2q)i+(q+p)j=2kg×(ij)m/s2(p+2q)\mathbf{i} + (q+p)\mathbf{j} = 2\,\text{kg} \times (\mathbf{i}-\mathbf{j})\,\text{m/s}^{-2}
  3. Coefficient Equations: We can now equate the coefficients of ii and jj from both sides of the equation.\newlineFor ii: p+2q=2×1p + 2q = 2 \times 1\newlineFor jj: q+p=2×(1)q + p = 2 \times (-1)
  4. Solving for p: Let's solve the first equation for p.\newlinep+2q=2p + 2q = 2\newlinep=22qp = 2 - 2q
  5. Plugging in Values: Now, let's plug the value of pp into the second equation.q+(22q)=2q + (2 - 2q) = -2q+22q=2q + 2 - 2q = -2

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