233,435 views
41 votes
41 votes
could you help with question 5. Your solutions to the word problems in volving Newton's Laws should have the following features:Each solution should begin with one or more free body diagrams with a sign convention.The solution process should follow the GRASP process.Formulae should always be used in a three-step process: formula with letter variables, substitution of values, and then the answer.Answers should be expressed with the correct number of significant digits and with the direction if required.

could you help with question 5. Your solutions to the word problems in volving Newton-example-1
User Ben Jonson
by
2.8k points

1 Answer

13 votes
13 votes

ANSWER:

(a) 20 m/s^2

(b) 250 m

Explanation:

Given:

Mass (m) = 250 g = 0.25 kg

Force (F) = 20 N

Frictional force (Ff) = 15 N

(a)

The net force on the block is:


\begin{gathered} F_(net)=F-F_f \\ F_(net)=20-15 \\ F_(net)=5\text{ N} \end{gathered}

We know that:


\begin{gathered} F=m\cdot a \\ \text{ We replacing} \\ 5=0.25\cdot a \\ a=(5)/(0.25) \\ a=20\text{ m/s}^2 \end{gathered}

(b)

We can calculate the partial distance from the following equation:

initial velocity (u) = 0 (start from rest)


\begin{gathered} s=ut+(1)/(2)at^2 \\ \text{ we replacing} \\ s=0\cdot5+(1)/(2)\cdot20\cdot5^2 \\ s=250\text{ m} \end{gathered}

User Dannyrosalex
by
2.6k points