Physics

Problem

A block of mass

2\,\text{kg}

is said to move with a uniform acceleration of

20\,\text{cm}\,\text{s}^{-2}

. A student writes the force as

F = 2 \times 20 = 40\,\text{N}

. Which of the following identifies the error in this calculation? a)

F

should have been calculated using

F=ma^{2}

, so the acceleration ought to be squared. b) The mass must first be converted to grams because the acceleration is given in

\text{cm}\,\text{s}^{-2}

. c) The acceleration must be converted to

\text{m}\,\text{s}^{-2}

before it is substituted in the formula. d) To convert properly, the student should have multiplied the acceleration by

100

rather than using it directly.