No Title
PH111 - MECHANICS
Solution to Quiz 8
Tuesday 10/20/15
Name
O101: periods 1,2
CM#
A block of mass 1.80 kg is placed on a smooth horizontal floor and experiences two additional external forces given by
F
1
=
(7.52 N)
^
i
-
(2.74 N)
^
j
F
2
=
-
(4.00 N)
^
i
(a) Draw a figure indicating ALL forces acting on the block and calculate the net force acting on the block.
F
net
=
F
1
+
F
2
+
n
+
W
=
(7.52
-
4.00)N
^
i
+[n
-
2.74 N
-
(1.80 kg) (9.80 N/kg)]
^
j
=
(3.52 N)
^
i
with n=20.4 N.
(b) What is the total work done on the block when it has been displaced 1.50 m?
W
net
=
(3.52 N)(1.50 m)
=
+5.28 J
(c) Assuming that the block started from rest, what was its speed after being displaced 1.50 m?
W
=
D
K
5.28 K
=
1
2
(1.80 kg)v
2
f
-
0
v
f
=
2.42 m/s
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On 28 Oct 2015, 09:12.