الرئيسية
:bsmallah:
:tahiaa:
THE IUG PHYSA 1301 DEPT. OF PHYSICS
DATE:21-11-2006 SECOND MID EXAM. TIME:1-Hr
اسم المدرس:………….……. الرقم الجامعي:…………… اسم الطـالب:…………… ……….
Part I Q1 Q2 Q3 Total
PART I: choose the correct answer (18×4=72 pts)
1) The centripetal acceleration is due to the change in
a) velocity b) speed c) the direction of v d) all of them
2) The tangential acceleration is due to the change in
a) velocity b) speed c) the direction of v d) all of them
3) A particle moves with constant speed of 4 m/s around a circle of radius 2 m. Its acceleration is
a) zero b) 8 m/s2 c) 1 m/s2 d) 2 m/s2
4) A small ball of mass 1.2 kg, attached to a string of length 0.8 m, moves in a vertical circle. Its speed at point A is 4 m/s, the tension at point A is
a) 20 N b) 11.8 N c) 12.2 N d) 53.8 N
5) Refering to the previous problem, if the speed of the ball at point B is 2 m/s, the tangential acceleration of the ball at point B is
a) 5 m/s2 b) 9.8 m/s2 c) 14.8 m/s2 d) 11 m/s2
6) A car of mass 1500 kg rounds a flat curve of radius 30 m with a speed of 12 m/s. If the coefficient of friction between the tires and the road are . The frictional force between the car and the road is
a) 8820 N b) 7200 N c) 5880 N d) zero
7) The unit of the gravitational constant G is
a) N b) N/m2 c) N.m2/kg2 d) N/kg2
8) If a satellite moves about the earth's in a circular orbit with constant speed, then
a) Its velocity is constant. b) The net force on it is zero.
c) Its acceleration is toward the earth. d) Its velocity is toward the earth.
9) The unit of 1 J is equal to
a) 1 N/m b) 1 N/s c) 1 Watt d) 1 N.m
10) The unit of 1 Watt is equal to
a) 1 J.s b) 1 N.m c) 1 kg m2/s3 d) 1 N/s
11) A particle moves 6 m in the +x direction by the effect of a force F=4i + 3j. The work done by this force is
a) 24 J b) 18 J c) 30 J d) we need the angle between F and S
12) A spring of constant 50 N/m is hung vertically from the ceiling. When a 0.5-kg block hangs at rest from it, the spring is extended 10 cm. The work done by the spring is
a) -0.5 J b) -0.25 J c) 0.5 J d) 0.25 J
13) A 4-kg block starts from the bottom of an incline with a speed of 3 m/s and comes to rest 2 m up the incline. The net work done on the block is
a) 6 J b) 8 J c) 12 J d) 18 J
14) A force is conservative if its work
a) depends on the initial and the final points of the motion. b) is zero.
c) depends on the path followed. d) Non of these.
15) The mechanical energy of a system is conservative only when
a) no external force acts on the system b) no frictional force acts on the system.
c)no work done by the nonconservative forces d) no nonconservative forces act on the system
16) The ball of the simple pendulum shown is released from rest at point A. Its speed at point B is
a)
b)
c)
d)
17) The x-coordinates of the center of mass of the two particles shown is
a) 1 m b) 1.5 m c) 3 m d) 0.5 m
18) A block rests on a cart that slides along a smooth horizontal surface. If the block falls off the crate with zero speed relative to the cart, the speed of the cart
a) will not be changed. b) will increase.
c) will decrease. d) depends on wether the surface of the crate is smooth or rough.
PART II: Solve the following two problems (2×15=30 pts)
Q1) A small block of mass m slides without friction around a loop-to-loop of radius 3 m, as shown in the figure. Find the minimum value of h for the block not to fall at the top of the loop.
Q2) A block of mass 10 kg sliding on a frictionless surface explodes into two equal pieces. One piece goes north at 6 m/s, and the other piece goes 30o north of west at 4 m/s. What was the original velocity of the block?[right][center]
:tahiaa:
THE IUG PHYSA 1301 DEPT. OF PHYSICS
DATE:21-11-2006 SECOND MID EXAM. TIME:1-Hr
اسم المدرس:………….……. الرقم الجامعي:…………… اسم الطـالب:…………… ……….
Part I Q1 Q2 Q3 Total
PART I: choose the correct answer (18×4=72 pts)
1) The centripetal acceleration is due to the change in
a) velocity b) speed c) the direction of v d) all of them
2) The tangential acceleration is due to the change in
a) velocity b) speed c) the direction of v d) all of them
3) A particle moves with constant speed of 4 m/s around a circle of radius 2 m. Its acceleration is
a) zero b) 8 m/s2 c) 1 m/s2 d) 2 m/s2
4) A small ball of mass 1.2 kg, attached to a string of length 0.8 m, moves in a vertical circle. Its speed at point A is 4 m/s, the tension at point A is
a) 20 N b) 11.8 N c) 12.2 N d) 53.8 N
5) Refering to the previous problem, if the speed of the ball at point B is 2 m/s, the tangential acceleration of the ball at point B is
a) 5 m/s2 b) 9.8 m/s2 c) 14.8 m/s2 d) 11 m/s2
6) A car of mass 1500 kg rounds a flat curve of radius 30 m with a speed of 12 m/s. If the coefficient of friction between the tires and the road are . The frictional force between the car and the road is
a) 8820 N b) 7200 N c) 5880 N d) zero
7) The unit of the gravitational constant G is
a) N b) N/m2 c) N.m2/kg2 d) N/kg2
8) If a satellite moves about the earth's in a circular orbit with constant speed, then
a) Its velocity is constant. b) The net force on it is zero.
c) Its acceleration is toward the earth. d) Its velocity is toward the earth.
9) The unit of 1 J is equal to
a) 1 N/m b) 1 N/s c) 1 Watt d) 1 N.m
10) The unit of 1 Watt is equal to
a) 1 J.s b) 1 N.m c) 1 kg m2/s3 d) 1 N/s
11) A particle moves 6 m in the +x direction by the effect of a force F=4i + 3j. The work done by this force is
a) 24 J b) 18 J c) 30 J d) we need the angle between F and S
12) A spring of constant 50 N/m is hung vertically from the ceiling. When a 0.5-kg block hangs at rest from it, the spring is extended 10 cm. The work done by the spring is
a) -0.5 J b) -0.25 J c) 0.5 J d) 0.25 J
13) A 4-kg block starts from the bottom of an incline with a speed of 3 m/s and comes to rest 2 m up the incline. The net work done on the block is
a) 6 J b) 8 J c) 12 J d) 18 J
14) A force is conservative if its work
a) depends on the initial and the final points of the motion. b) is zero.
c) depends on the path followed. d) Non of these.
15) The mechanical energy of a system is conservative only when
a) no external force acts on the system b) no frictional force acts on the system.
c)no work done by the nonconservative forces d) no nonconservative forces act on the system
16) The ball of the simple pendulum shown is released from rest at point A. Its speed at point B is
a)
b)
c)
d)
17) The x-coordinates of the center of mass of the two particles shown is
a) 1 m b) 1.5 m c) 3 m d) 0.5 m
18) A block rests on a cart that slides along a smooth horizontal surface. If the block falls off the crate with zero speed relative to the cart, the speed of the cart
a) will not be changed. b) will increase.
c) will decrease. d) depends on wether the surface of the crate is smooth or rough.
PART II: Solve the following two problems (2×15=30 pts)
Q1) A small block of mass m slides without friction around a loop-to-loop of radius 3 m, as shown in the figure. Find the minimum value of h for the block not to fall at the top of the loop.
Q2) A block of mass 10 kg sliding on a frictionless surface explodes into two equal pieces. One piece goes north at 6 m/s, and the other piece goes 30o north of west at 4 m/s. What was the original velocity of the block?[right][center]
