A block slides on a horizontal surface with an initial speed of

PHYSICS · Single correct · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

2\,\text{kg}

block slides on a horizontal surface with an initial speed of

10\,\text{m\,s}^{-1}

. For the first

3\,\text{m}

the coefficient of kinetic friction is

0.10

, and for the next

5\,\text{m}

it is

0.25

. What is the speed of the block after it has completed the total

8\,\text{m}

? (Take

g=10\,\text{m\,s}^{-2}

.) (a)

8.5\,\text{m\,s}^{-1}

(b)

6.2\,\text{m\,s}^{-1}

(c)

7.7\,\text{m\,s}^{-1}

(d)

8.3\,\text{m\,s}^{-1}