SAT物理模拟试题.doc

SAT模拟试题(1)
1.An object that’s moving with constant speed travels once around a circular path.True statements about this motion include which of the following?
A.The displacement is zero B. The average speed is zero
C. The acceleration is zero D. None of the above
A
2.Which of the following must always be true?
1.If an object’s acceleration is constant,then it must move in a straight line
2.If an object’s acceleration is zero,then its speed must remain constant
3.If an object’s speed remains constant,then its acceleration must be zero.
A.1 and 2 only B.1 and 3 only C.2 only D.3 only E.2 and 3 only
C
4.A frictionless inclined plane of length 20m has a maximum vertical height of 5m. If an object of mass 2 kg is planced on the plame . Which of the following best approximates the net force it feels?
A.5N B.10N C.15N D.20N E.30N
A
5.A person who weighs 800N steps onto a scale that is on the floor of an elevator car. If the elevator accelerates upward at a rate of 5 m/s, what will the scale read?
A.400N B.800N C.1000N D.1200N E.1600N
D
6.A person standing on a horizontal floor feels two forces: the downward pull of gravity and the upward supporting force from the floor. There two forces
A. have equal magnitudes and from an action /reaction pair
B. have equal magnitudes but do not from an action /reaction pair
C. have unequal magnitudes and from an action /reaction pair
D. have unequal magnitudes and do not from an action /reaction pair
E.None of the above
B
7.How long would it take a car,starting from rest and accelerating uniformly in a straight line at 5m/s,to cover a distance of 200m?
A.9s B 10.5s C.12.0s D.15.5s E.20.0s
A
8.A rock is dropped off a cliff and strikes the ground with an impact velocity of 30m/s.How high was the cliff?
A.15m B.20m C.30m D.45m E.60m
D
9.A soccer ball at rest on the ground,is kicked with an initial velocity of 10m/s at a launch angle of 30.Calculate its total flight time , assuming that air resistance is negligible.
A.0.5s B.1s C.1.7s D.2s E.4s
B
10.If all of the forces acting on an object balance so that the net force is zero , then
A.the object must be at rest
B. the object’s speed will decrease
C. the object will follow a parbolic trajectory
D. the object’s direction of motion can change,but its speed cannot
E.None of the above
E
11.The coefficient of static friction between a box and a ramp is 0.5. The ramp’s incline angle is 30.If the box is placed at rest on the ramp, box will
A. accelerate down the ramp
B. accelerate briefly down the ramp but then slow down and stop
C.move with constant velocity down the ramp
D.not move
E.Cannot be determined from the information given
A
12.A 20N block is being pushed across a horizontal table by an 18N force . If the coefficient of kinetic friction between the block and the table is 0.4. find he acceleration of the block
A.0.5 m/s B.1 m/s C.5 m/s D.7.5 m/s E.9m/s
C
13.A stone is thrown horizontally with an initial speed of 30m/s from a bridge.Find the stone’s total speed when it enters the water 4 seconds later(Ignore air resistance.)
A.30m/s B.40m/s C.50m/s D.60m/s E.70m/s
C
14.Which one of the following statements is true concerning the motion of an ideal projectile launched at an angle of 45 to the borizontal?
A.The acceleration vector points opposite to the velocity vector on the way up and in the same direction as the velocity vector on the way down
B.The speed at the top of the trajectory is zero.
C.The object’s total speed remains constant during the entire flight
D.The horizontal speed decreases on the way up and increases on the way down
E.The vertical speed decreases on the way up and increases on the way down
E
15.Which pair of forces can produce a resultant of 15 newtons?
A.20N,20N B.25N5N C.5N,5N D.7N,7N E.5N,3N
A
16.Two crates are stacked on top of each other on a horizontal floor , crate #1 is on the bottom , and crate #2 is on the top . Both crates have the same mass . Compared with the strength of the force Fnecessary to push only crate #1 at a constant speed across the floor, the strength of the force Fnecessary to push the stack at the same constant speed across the floor is greater than Fbecause
A.the force of the floor on crate #1 is greater
B.the coefficient of kinetic friction between crate #1 and the floor is greater
C.the force of kinetic friction. But not the normal force, on crate #1 is greater
D. the coefficient of static friction between crate #1 and the floor is greater
E.the weight of crate #1 is greater
A
17.A crate of mass 100kg is at rest on a horizontal floor. The coefficient of static friction between crate and the floor is 0.4, land the coefficient of kinetic friction is 0.3. A force F of magnitude 344N is then applied to the crate,parallel to the floor. Which of the following is true?
A.The crate will accelerate across the floor at 0.5m/s
B.Thestatic friction force , which is the reaction force to F as guaranteed by Newton’s third law . will also have a magnitude of 344N
C.The crate will slide across the floor at a constant speed of 0.5m/s
D.The crate will not move
E None of the above
D
18.A block of mass m is at rest on a frictionless, horizontal table placed in a laboratory on the surface of the earth . An identical block is at rest on a frictionless, horizontal table placed on the surface of the moon . Let F be the net force necessary to give the earth-hound block an acceleration of a across the table . Given that g is one sixth of g, the force necessary to give the moon-boud block the same acceleration a across the table is
A.F/12 B.F/6 C.F/3 D.F E.6F
D
19.As the angle between two concurrent forces increases,the magnitude of their resultant
A.increases only B.decreases and then increases
C.increases and then decreases D.remains the same E.decreases only
E
20.A girl walks 2 meters north, 4 meters west,and 2 meters south.Her final displacement is
A.4 m east B.4m west C.2m north D.2m south E.5m northwest
B
21.A cart is pulled by a rope making an angle of 45 to the horizontal.If 100 newtons of force are applied to the rope,the magnitude of the horizontal component force is approximately
A.45N B.141N C.100N D.80N E.71N
E
22.A moon of mass m orbits a plant of mass 100m. Let the strength of the gravitational force exerted by the planet on the moon be denoted by F,and let the strength of the gravitational force exerted by the moon on the planet be F.Which of the following is true?
A. F=100 F B.10 F= F C. F= F. D. F.=10 F E. F.=100F
23.At the surface of the earth , an object of mass m has weight w . If this object is transported to an altitude that’s twice the radius of the earth , then , at the new location
A. its mass is m/2 and its weight is w/2 B. its mass is m and its weight is w/2
C.its mass is m/2 and its weight is w/4 D. .its mass is m and its weight is w/4
E. .its mass is m and its weight is w/9
E
24.If the distance between two point particles is doubled, then the gravitational force between them
A.decreases by a factor of 4 B. decreases by a factor of 2
C. increases by a factor of 2 D. increases by a factor of 4
E.Cannot be determined without knowing the masses
25. The resultant of a 3-newton and a 4-newton force acting simultaneously on an object at right angles to each other is,in newtons
A.0 B.1 C.3.5 D.5 E.7
D
26.Two force act together on an object.The magnitude of their resultant is least when the angle between the forces is
A.0 B.45 C.60 D.90 E.180
E
27.The resultant of a 5-newton and a 12-newton force acting simultaneously on an object in the same direction is,in newtons.
A.0 B.5 C.7 D.13 E.17
E
28. An object is moving around a circle of radius 1.5 meters at a constant velocity of 7 meters per second. The frequency of the motion, in revolution per second, is
A.0.24 B.0.53 C.0.67 D.0.74 E.0.98
D
29.An object undergoes uniform accelerated motion. If the radius of the path is 2 meters and the period is equal to 4 seconds, the magnitude of the centyipetal acceleration is equal to
A.5m/s B.10 m/s C.20 m/s D.25 m/s E.30 m/s
A
30.An object undergoes uniform accelerated motion. If the radius of the path is equal to 1.5 meters and the magnitude of the centripetal acceleration is equal to 6 m/s,the magnitude of the tangential velocity is equal to
A.3m/s B.4 m/s C.5 m/s D.6 m/s E.9 m/s
A