Tuesday, October 04, 2011
7:22 AM
1. A child holds a sled at rest on a frictionless snow-covered hill with
a rope. The hill has an angle of 25 degrees. If the sled has a
weight of 77 N, find the tension in the rope and the normal force
exerted on the sled by the hill. See Ex 4.6 of Alg book or Ex 4.3
Calc book?
2. A car of mass m is on an icy driveway angled at 25 degrees. (a)
Find the acceleration of the car if the driveway is frictionless. (b)
If the driveway is not frictionless and the car remains motionless,
find the static coefficient of friction for the car and driveway.
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A 3-kg block starts from rest at the top of a 30 degree incline and
slides 2 meters down the incline in 1.5 seconds. Find (1) The
acceleration of the block (2) the coefficient of kinetic friction between
the block and the incline, (3) the frictional force acting on the block
and (4) the speed of the block after it has slid 2 meters.
Two boxes of fruit on a frictionless horizontal surface are
connected by a light string as shown on the board where m1
=10 kg and m2 =20 kg. A force of 50 N is applied to the 20 kg
box. (1) Determine the acceleration of each box. (2)
Determine the tension in the string between the boxes.
Two boxes of fruit on a horizontal surface are connected by
a light string as shown. The masses are as follows: m1 =10
kg and m2 =20 kg. The coefficient of friction between each
box and the table is 0.1. A force of 50 N is applied to the 20
kg box. (1) Determine the acceleration of each box. (2)
Determine the tension in the string between the boxes.
#37 cp page 112 A 1000 N crate is being pushed across a level
floor at a constant speed by a force F of 300 N at an angle of 20
degrees below horizontal as show in the picture. (1) What is
the coefficient of friction between the crate and floor?
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#37 cp page 112 A 1000 N crate is being PULLED across a level
floor by the same force F of 300 N at an angle of 20 degrees
above horizontal as show in the picture below. Assume that
the coefficient between the crate and floor is 0.256 like we just
found it to be. (1) What is the normal force of the crate? (2)
What is the force of friction acting on the crate? (3) What is
the acceleration of the crate?
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