The correct equation of motion is —

1. v = u + at
2. S = ut + $\dfrac{1}{2}$ at²
3. v² = u² + 2aS
4. All of these.

When a body starts from rest, the equation of motion takes the form:

1. v = u
2. v = at
3. v = $\dfrac{1}{2}$at²
4. S = ut + $\dfrac{1}{2}$ at²

A car acquires a velocity of 54 ms^-1 in 20 s starting from rest, then its acceleration is:

1. 5.4 ms^-2
2. 2.7 ms^-2
3. 7.2 ms^-2
4. 2.0 ms^-2

A particle starts to move in a straight line from a point with a velocity 10 ms^-1 and acceleration -2.0 ms^-2. Its position at t = 5 s will be :

1. 5 m
2. 10 m
3. 20 m
4. 25 m