WERABE UNIVERSITY
COLLEGE OF NATURAL AND COMPUTATIONAL SCEINCE
DEPARTMENT OF PHYSICS
MECHACHANICS AND HEAT ASSIGNMENT-II (15%)
1. In Figure bellow the weight w is 60 N.
(a) What is the tension in the diagonal string?
(b) Find the magnitudes of the horizontal forces 𝐹⃗1 and 𝐹⃗2 that must be applied to
hold the system in the position shown.
2. Besides its weight, a 2.80-kg object is subjected to one other constant force. The
object starts from rest and in 1.20 s experiences a displacement of (4.2 𝒊̂ − 3.30 𝒋̂) 𝑚,
where the direction of 𝒋̂ is the upward vertical direction. Determine the other force.
3. Two objects are connected by a light string that passes over a frictionless pulley, as in
Figure bellow. Draw free-body diagrams of both objects. If the incline is frictionless
and if 𝑚1 = 2 𝑘𝑔, 𝑚2 = 6 𝑘𝑔, and 𝜃 = 55°, find
(a) The accelerations of the objects,
(b) The tension in the string
(c) The speed of each object 2.00 s after being released from rest.
4. A 1.3 kg toaster is not plugged in. The coefficient of static friction between the toaster
and a horizontal countertop is 0.35. To make the toaster start moving, you carelessly
pull on its electric cord.
(a) For the cord tension to be as small as possible, you should pull at what angle
above the horizontal?
(b) With this angle, how large must the tension be?