Question

A car travels for 10s at a steady speed of 20 m/s along a straight road. The traffic lights ahead change to red, and the car slows down with a constant deceleration, so that it halts after a further 8s.

Answer 1

Answer:

The right solution is "2.5 m/s²". A further explanation is given below.

Explanation:

The given values are:

Initial velocity,

= 20 m/s

Final velocity,

= 0 m/s

Time,

= 8 s

As we know,

⇒  $Acceleration=\frac{Final \ velocity-Initial \ velocity}{2}$

On substituting the values, we get

⇒                       $=\frac{0-20}{8}$

⇒                       $=\frac{-20}{8}$

⇒                       $=-2.5 \ m/s^2$