Study Guide to test IlI 1. To get off a frozen, frictionless lake, a 65-kg perso
ID: 1775300 • Letter: S
Question
Study Guide to test IlI 1. To get off a frozen, frictionless lake, a 65-kg person takes off a 0.150-kg shoe and throws it horizontally, directly away from the shore with a speed of 2.00 m/s. If the person is 5.00 m from the shore, how long does he take to reach it? (in minutes) A0.45-kg piece of putty is dropped from a high of 2.5 m above a flat surface. When it hits the surface, the putty comes to rest in 0.30s. What is the average force exerted on the putty by surface? A fisherman reels in 12.0 m of line while landing a fish, using a constant forward pull of 25.0 N How much work does the tension in the line do on the fish? A 12.0 N package of whole wheat flour is suddenly placed on the pan of a scale such as you find in grocery stores. The pan is supported from below by a vertical spring of force constant 325 N/m. If the pan has negligible weight, find the maximum distance the spring will be compressed if no energy is dissipated by friction. At 7.35 cents per kilowatt-hour what does it cost to operate a 10.0 hp motor for 8.00 h? What does it cost to leave 75 W light burning 24 hours a day? A 20.0 box is pulled along a rough horizontal surface with rope at a constant speed 8 m/s. The rope is parallel to the floor and the coefficient of kinetic friction between the box and the floor is 0.200. What power must the rope supply to the box? Where does this energy go? Three odd-shaped blocks of chocolate have folowing masses and center-of-mass coordinates (1) 0.300 kg, (0.200 m, 0.300 m); (2) 0.400 kg, (0.100 m,-0.400 m); (3) 0.200 kg, (-0.300 m, 0.600 m). Find the coordinates of center of mass of the system of three chocolate blocks. 2. 3. 4. S. 6. 7. 8. A hungry 11.5 kg predator fish is coasting from west to east at 75.0 cm/s when it suddenly swallows a 125 kg fish swimming from north to south at 3.60 m/s. Find the magnitude and direction of the velocity of the large fish just after it snapped up this meal. Ignore any effects due to the drag of the waterExplanation / Answer
1) using conservation of momentum
0=65*v-0.150*2
slove for v
0.0004615m/s
to travel 5km
in 181 minutes thats over 3hours.
2)the direction is upward direction
3) work done=force*distance
=25*12
=300n-m.
4)assuming the load is 12.0kg
the spring is comnpressed as the load is released
PE lost (mgh) by load=strain energy gained by spring
at max compression KE=0
mgh=1/2ke2
e2=2mghe/k
e=2mghe/k
=2*12*9.80/325n/m
0.723n/m.
5) 10*746
=7460m
(7460*8)=59680
59.680
(59.680*7.3)/100
=$4.3
(75*24)=1800
1.8*7.3=13.14c
7) m1+m2+m3=0.300+0.400+0.200=0.900
x-axis=(m1*1+m2*2+m3*3)
(0.300*0.200+0.400*0.100+0.200*-0.300)=0.04
y-axis=(0.300*0.300+0.400*-0.400+0.200*0.600)=0.05.