A car moves from \(X\) to \(Y\) with a uniform speed \(v_u\) and returns to \(X\) with a uniform speed \(v_d.\) The average speed for this round trip is:
1. \(\frac{2 v_{d} v_{u}}{v_{d} + v_{u}}\)
2. \(\sqrt{v_{u} v_{d}}\)
3. \(\frac{v_{d} v_{u}}{v_{d} + v_{u}}\)
4. \(\frac{v_{u} + v_{d}}{2}\)

A particle moves along a straight line OX. At a time \(t\) (in seconds), the displacement \(x\) (in metres) of the particle from O is given by \(x= 40 +12t-t^3\). How long would the particle travel before coming to rest?

A ball is dropped vertically from a height \(h\) above the ground. It hits the ground and bounces up vertically to a height of \(\frac{h}{2}\). Neglecting subsequent motion and air resistance, its velocity \(v\) varies with the height \(h\) as:
[Take vertically upwards direction as positive.]

1.		2.
3.		4.

A car \(A\) is traveling on a straight level road at a uniform speed of \(60\) km/h. It is followed by another car \(B\) which is moving at a speed of \(70\) km/h. When the distance between them is \(2.5\) km, car \(B\) is given a deceleration of \(20\) km/h². After how much time will car \(B\) catch up with car \(A\)?
1. \(1\) hr
2. \(\frac{1}{2}\) hr
3. \(\frac{1}{4}\) hr
4. \(\frac{1}{8}\) hr

The graph of displacement time is given below.

Its corresponding velocity-time graph will be:

1.		2.
3.		4.

A particle moves in a straight line with a constant acceleration. It changes its velocity from \(10\) ms^-1 to \(20\) ms^-1 while covering a distance of \(135\) m in \(t\) seconds. The value of \(t\) is:

A ball is dropped from a high-rise platform at \(t=0\) starting from rest. After \(6\) seconds, another ball is thrown downwards from the same platform with speed \(v\). The two balls meet after \(18\) seconds. What is the value of \(v\)?

A stone falls freely under gravity. It covers distances \(h_1,~h_2\) and \(h_3\) in the first \(5\) seconds, the next \(5\) seconds and the next \(5\) seconds respectively. The relation between \(h_1,~h_2\) and \(h_3\) is:

A particle of unit mass undergoes one-dimensional motion such that its velocity varies according to \(v(x)= βx^{- 2 n}\) where \(\beta\) and \(n\) are constants and \(x\) is the position of the particle. The acceleration of the particle as a function of \(x\) is given by:
1. \(- 2 nβ^{2} x^{- 2 n - 1}\)
2. \(- 2 nβ^{2} x^{- 4 n - 1}\)
3. \(- 2 \beta^{2} x^{- 2 n + 1}\)
4. \(- 2 nβ^{2} x^{- 4 n + 1}\)
${\mathrm{}}^{}$

If the velocity of a particle is \(v=At+Bt^{2},\) where \(A\) and \(B\) are constants, then the distance travelled by it between \(1~\text{s}\) and \(2~\text{s}\) is: