Download Chapter 4 Homework

Chapter 4 Homework
1.
A net force of
2.
A 4.0-kg object is subjected to two constant forces,
acts on a 1.5 kg object. Find the acceleration
.
. The object is at rest at the
origin at time t = 0. (a) What is the object’s acceleration? (b) What is its velocity at time t = 3.0 s? (c) Where
is the object at time t = 3.0 s?
3.
A ball weighing 100-N is shown suspended from a system of cords (Figure 4-39). What are the tensions in
the horizontal and angled cords?
4.
A 20.0 kg box rests on a frictionless ramp with a 15.0° slope. The mover pulls on a rope attached to the box
to pull it up the incline (Figure 4-44). If the rope makes an angle of 40.0° with the horizontal, what is the
smallest force F the mover will have to exert to move the box up the ramp?
5.
A horizontal force of 100 N pushes a 12-kg block up a frictionless incline that makes an angle of 25° with the
horizontal. (a) What is the normal force that the incline exerts on the block? (b) What is the magnitude of
acceleration of the block?
Chapter 4 Homework
6.
A block of mass m slides across a frictionless floor and then up a frictionless ramp (Figure 4-48). The angle
of the ramp is
and the speed of the block before it starts up the ramp is
. The block will slide up to
some maximum height h above the floor before stopping. Show that h is independent of m and
an expression for h in terms of
7.
by deriving
and g.
Two blocks are in contact on a frictionless horizontal surface. The blocks are accelerated by a single
horizontal force
applied to one of them (Figure 4-52). Find the acceleration and the contact force of block
1 on block 2 (a) in terms of F, m1 and m2 and (b) for the specific values F = 3.2 N, m1 = 2.0 kg and m2 = 6.0
kg.
8.
Two objects are connected by a massless string, as shown in Figure 4-54. The incline and the massless pulley
are frictionless. Find the acceleration of the objects and the tension in the string (a) in terms of
and for (b)
= 30° and m1 = m2 = 5.0 kg.
, m1 and m2,