5 A particle \(P\) of mass 2 kg moving on a horizontal straight line has displacement \(x \mathrm {~m}\) from a fixed point \(O\) on the line and velocity \(v \mathrm {~m} \mathrm {~s} ^ { - 1 }\) at time \(t\) s. The only horizontal force acting on \(P\) is a variable force \(F \mathrm {~N}\) which can be expressed as a function of \(t\). It is given that
$$\frac { v } { x } = \frac { 3 - t } { 1 + t }$$
and when \(t = 0 , x = 5\).
- Find an expression for \(x\) in terms of \(t\).
\includegraphics[max width=\textwidth, alt={}, center]{1eb2ef87-e858-41c1-8e96-75fb2222b57a-08_2718_38_106_2009}
\includegraphics[max width=\textwidth, alt={}, center]{1eb2ef87-e858-41c1-8e96-75fb2222b57a-09_2723_33_99_21} - Find the magnitude of \(F\) when \(t = 3\).
\includegraphics[max width=\textwidth, alt={}, center]{1eb2ef87-e858-41c1-8e96-75fb2222b57a-10_559_1257_255_445}
A particle \(P\) of mass 0.05 kg is attached to one end of a light inextensible string of length 1 m . The other end of the string is attached to a fixed point \(O\). A particle \(Q\) of mass 0.04 kg is attached to one end of a second light inextensible string. The other end of this string is attached to \(P\).
The particle \(P\) moves in a horizontal circle of radius 0.8 m with angular speed \(\omega \operatorname { rad~s } ^ { - 1 }\). The particle \(Q\) moves in a horizontal circle of radius 1.4 m also with angular speed \(\omega \mathrm { rad } \mathrm { s } ^ { - 1 }\). The centres of the circles are vertically below \(O\), and \(O , P\) and \(Q\) are always in the same vertical plane. The strings \(O P\) and \(P Q\) remain at constant angles \(\alpha\) and \(\beta\) respectively to the vertical (see diagram). - Find the tension in the string \(O P\).
\includegraphics[max width=\textwidth, alt={}, center]{1eb2ef87-e858-41c1-8e96-75fb2222b57a-10_2716_38_109_2012}
\includegraphics[max width=\textwidth, alt={}, center]{1eb2ef87-e858-41c1-8e96-75fb2222b57a-11_2725_35_99_20} - Find the value of \(\omega\).
- Find the value of \(\beta\).