In our first example we will consider a very simple application of Newton’s seco
ID: 1331688 • Letter: I
Question
In our first example we will consider a very simple application of Newton’s second law. A worker with spikes on his shoes pulls with a constant horizontal force of magnitude 20 N on a box with mass 40 kg resting on the flat, frictionless surface of a frozen lake. What is the acceleration of the box?
a) If the box starts from rest and the worker pulls with a force of 30 N , what is the speed of the box after it has been pulled a distance of 0.34 m ?
Express your answer in meters per second to two significant figures.
Explanation / Answer
The newton second law
F = m a
acceleration
a = F/ m = 20 N /40kg = 0.5 m/s^2
b)
acceleration a = F / m = 30 N / 40 kg = 0.75m/s^2
initial speed Vi = 0 , distance d = 0.34m
V^2 - Vi^2 = 2 a d
V^2 - 0 = 2 (0.75)(0.34)
V = 0.714m/s
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.