Homework 1 Flashcards
(47 cards)
1
Q
Your car gets 30.2 mi/gal on a trip. How many kilometers/liter did it get? A) 7.97 km/L B) 12.8 km/L C) 18.0 km/L D) 28.2 km/L E) 48.6 km/L
A
B) 12.8 km/L
2
Q
A nanosecond is: A) 109s B) 10−9s C) 10−10s D) 10−11s E) 10−12s
A
B) 10^-9s
3
Q
The SI base unit for mass is the: A) gram B) pound C) kilogram D) ounce E) kilopound
A
C) kilogram
4
Q
5.0×104)×(3.0×106) = A) 1.5×109 B) 1.5×1010 C) 1.5×1011 D) 1.5×1012 E) 1.5×1013
A
C) 1.5x10^11
5
Q
The number of significant figures in 0.000330 is: A) 2 B) 3 C) 4 D) 5 E) 6
A
B) 3
6
Q
The number of significant figures in 650.0 is: A) 1 B) 2 C) 3 D) 4 E) 5
A
D) 4
7
Q
7.513 + 27.3 = A) 35 B) 34.8 C) 34.9 D) 34.81 E) 34.813
A
B) 34.8
8
Q
One mile is equivalent to 1609 m, so 65 mph (miles per hour) is: A) 210 m/s B) 21 m/s C) 71 m/s D) 8.2 m/s E) 29 m/s
A
E)29
9
Q
A sphere with a radius of 2.4 cm has a surface area of: A) 9.6×10−3m2 B) 7.2×10−3m2 C) 3.6×10−3m2 D) 1.2×10−2m2 E) 0.14 m2
A
B) 7.2 x 10^-3 m^2
10
Q
One meter is equivalent to 3.281 ft. A cube with edges of 0.75 ft has volume: A) 1.2×10−2m3 B) 2.6×10−2m3 C) 0.51 m3 D) 9.5×10−2m3 E) 0.18 m3
A
A) 1.2 x 10^-2 m^3
11
Q
During a short interval of time the speed of v in m/s of an automobile is given b yv=at+bt3+c/t, where the time t is in seconds. The units of a, b, and c are, respectively: A) m·s3; m·s4; s/m B) m/s2; s4/m; s/m2 C) m/s2; m/s4; m D) m/s3; m/s4; m/s E) m/s4; m/s3; m
A
B) m/s^2, m/s^4, m
12
Q
Suppose A=BC, where A has the dimensions L2/M3 and C has the dimensions L/T. Here M represents mass, L represents length, and T represents time. Then B has the dimensions: A) T/M B) L2/TM C) TM/L2 D) LT/M3 E) M/L2T
A
D) LT/M^3
13
Q
Suppose A=BmCn, where A has dimensions L2T, B has dimensions LT−1, and C has dimensions L2T2. Here M represents mass, L represents length, and T represents time. Then the exponents m and n, respectively (i.e.,m first, n second), have the values: A) 2/3; 1/3 B) 2; -1 C) 1/2; -2/3 D) 1/5; 3/5 E) 1/2; 3/4
A
E) 1/2; 3/4
14
Q
A particle moves along the x axis from xi to xf. Of the following values of the initial and final coordinates, which results in a negative displacement? A)xi= 4m;xf= -1m B)xi= 4m;xf= 8m C)xi= -4m;xf= 2m D)xi= -4m;xf= -3m E)xi= 2m;xf= 4m
A
A) xi = 4m; xf = -1m
15
Q
Two automobiles are 250 kilometers apart and traveling toward each other. One automobile is movingat 60 km/h and the other is moving at 40 km/h. In how many hours will they meet? A) 2.5 B) 2.0 C) 1.75 D) 1.5 E) 1.25
A
A) 2.5
16
Q
A car travels 60 kilometers at an average speed of 80 km/h and then travels 40 kilometers at an averagespeed of 60 km/h. The average speed of the car for this 100 km trip is: A) 50 km/h B) 60 km/h C) 70 km/h D) 80 km/h E) 90 km/h
A
C) 70 km/h
17
Q
The coordinates of a particle in meters is given by x(t) = 5.5 + 8.0t−3.0t3, wheretis in seconds. The particle is momentarily at rest at t=: A) 0.75 s B) 0.94 s C) 1.8 s D) 2.3 s E) 4.3 s
A
B) 0.94s
18
Q
An accelerating rocket ship starts from rest at t= 0 and moves along a straight line with velocity given by v=bt+ 2ct2, where b and c are constants. The expression for the distance traveled by this rocketship at timetfrom its initial (t= 0) position is: A) ct3 B)bt+ct3/3 C) 4bt2+ 8ct3 D)bt2/2 + 2ct3/3 E) 2.5ct
A
D) 4bt^2 + 8ct^3
19
Q
A ball is rolling up a slope. At the end of three seconds its velocity is 20 cm/s; at the end of sevenseconds its velocity is 2 cm/s. What is the average acceleration from the third to the seventh second? A) -2.5 cm/s2 B) -4.5 cm/s2 C) -5.5 cm/s2 D) -6.0 cm/s2 E) -6.67 cm/s2
A
B) -4.5 cm/s^2
20
Q
Each of four particles move along anxaxis. Their coordinates (in meters) as functions of time (inseconds) are given by particle 1:x(t) = 3.5−2.7t−2.7t2 particle 2:x(t) = 3.5 + 2.7t3 particle 3:x(t) = 3.5 + 2.7t2 particle 4:x(t) = 3.5−3.4t−2.7t3 Which of these four particles have constant acceleration?A) All four B) Only 1 and 2 C) Only 1 and 3 D) Only 3 and 4 E) None of them
A
C) only 1 and 3
21
Q
Each of four particles move along anxaxis. Their coordinates (in meters) as functions of time (in seconds) are given by particle 1:x(t) = 3.5−2.7t3 particle 2:x(t) = 3.5 + 2.7t3 particle 3:x(t) = 3.5 + 2.7t2 particle 4:x(t) = 3.5−3.4t−2.7t2 Which of these particles is speeding up fort >0? A) All four B) Only 1 C) Only 2 and 3 D) Only 2, 3 and 4 E) None of them
A
A) All four
22
Q
At time t= 0 a car has a velocity of 16 m/s. It slows down with an acceleration given by -0.50t, in m/s2 for t in seconds. At t= 6.0 s it has traveled: A) 58 m B) 68 m C) 78 m D) 88 m E) 98 m
A
C) 78 m
23
Q
The same car (referring to the previous problems) continues to decelerate at the same rate. At what value of t does it stop? A) 64 s B) 32 s C) 16 s D) 8.0 s E) 4.0 s
A
D) 8.0 s
24
Q
The same car (referring to the previous TWO problems) has traveled what distance between t= 0 and the time t when it stops? A) 12 m B) 54 m C) 85 m D) 110 m E) none of these
A
C) 85 m
25
```
Acceleration is sometimes expressed in multiples of g, where g= 9.8 m/s2. is the acceleration due to the Earth’s gravity. In a car crash, the car’s velocity may go from 26 m/s to 0 m/s in 0.15 s. In this crash, what is the magnitude of the average acceleration experienced by the driver?
A) 11 g
B) 18 g
C) 22 g
D) 25 g
E) none of these
```
B) 18 g
26
```
At a stop light, a truck traveling at 16 m/s passes a car as it starts from rest. The truck travels atconstant velocity and the car accelerates at 4.0 m/s2. How much time does the car take to catch up to the truck?
A) 5.0 s
B) 8.0 s
C) 12 s
D) 16 s
E) none of these
```
B) 8.0 s
27
```
An object is thrown straight up from ground level with initial speed of 50 m/s. Assuming g= 10 m/s2 its distance above ground level 3.0 s later is:
A) 55 m
B) 75 m
C) 95 m
D) 105 m
E) 145 m
```
D) 105 m
28
```
An object is thrown straight down with an initial speed of 2.0 m/s from a window which is 10.0 m above the ground. The time it takes the object to reach the ground is:
A) 0.80 s
B) 0.93 s
C) 1.2 s
D) 1.7 s
E) 2.0 s
```
C) 1.2 s
29
```
A projectile is shot vertically upward with a given initial velocity. It reaches a maximum height of 125 m. If, on a second shot, the initial velocity is doubled then the projectile will reach a maximum height of:
A) 500 m
B) 400 m
C) 250 m
D) 210 m
E) none of these
```
A) 500
30
For the functionf(x) = sin(x) + cos(x), what is the maximum value and at what values ofxdo thesemaxima occur?
A) max of 1.0; at x= 0,±π,±2π,±3π,...
B) max of 0.5; at x=±π,±2π,±3π,...
C) max of √2; at x=π/4, π/4±π, π/4±3π, π/4±5π,...
D) max of √2; at x=π/4, π/4±2π, π/4±4π, π/4±6π,...
E) max of√2; at x=π/4, π/4±π/2, π/4±π, π/4±3π/2,...
D) max of √2; at x=π/4, π/4±2π, π/4±4π, π/4±6π,...
31
```
The position of a particle is given by x(t) =Asin(ωt) +Bcos(ωt). What is the velocity of the particle at t=π/ω?A)ω(A−B)
B)ω2
C)ωB
D)−ωB
E)−ωA
```
E) -wA
32
```
For the function f(x) =√1 +a/x, what is the first derivative with respect to x?
A)−ax2√1 +a/x
B)−1√1 +a/x
C)a2√1 +a/x
D)−ax√1 +a/x
E)−a2x2√1 +a/x
```
E) −a2x2√1 +a/x
33
```
What is the value of ∫3/1 (x2+ 2/x2) dx?
A) 1
B) 7/3
C) 3
D) 10
E) 25/3
```
D) 10
34
If|~A+~B|2=A2+B2, then:
A) ~A and~B must be parallel and in the same direction
B) ~A and~B must be parallel and in opposite directions
C) either ~A or ~B must be zero
D) the angle between ~A and ~B must be 60◦
E) none of the above is true
E) none of the above is true
35
```
Vectors ~A and ~B lie in the xy plane. We can conclude that ~A=~B if:
A) A2x+A2y=B2x+B2y
B) Ax+Ay=Bx+By
C) Ax=Bx and Ay=By
D) Ay/Ax=By/Bx
E) Ax=Ay andBx=By
```
C) Ax=Bx and Ay=By
36
```
If~A= (3.0 m)ˆi−(9.0 m)ˆj, then ~A has magnitude:
A) 5.5 m
B) 6.5 m
C) 9.5 m
D) 11 m
E) 12 m
```
C) 9.5 m
37
```
The angle between~A= (25 m)ˆi+ (45 m)ˆjand the positivexaxis is:
A) 29◦
B) 61◦
C) 151◦
D) 209◦
E) 241◦
```
B) 61◦
38
```
Let ~A= (−2 m)ˆi+ (4 m)ˆj−(3 m)ˆk and ~B= (4 m)ˆi−(2 m)ˆj+ (3 m)ˆk. The vector difference ~D=~A−~B is:
A) (6 m)ˆi−(6 m)ˆj+ (6 m)ˆk
B) (−2 m)ˆi+ (4 m)ˆj−(4 m)ˆk
C) (2 m)ˆi−(4 m)ˆj+ (4 m)ˆk
D) (8 m)ˆi+ (12 m)ˆj−(3 m)ˆk
E) none of these
```
E) none of these
39
```
A particle goes from x=−2 m, y= 3 m, z= 4 m to x= 1 m, y=−1 m, z=−4 m. Its displacement is:
A) (1m)ˆi+ (2m)ˆj+ (8m)ˆk
B) (3m)ˆi−(4m)ˆj+ (3m)ˆk
C)−(3m)ˆi+ (4m)ˆj−(3m)ˆk
D) (3m)ˆi−(4m)ˆj−(8m)ˆk
E)−(3m)ˆi−(2m)ˆj
```
D) (3m)ˆi−(4m)ˆj−(8m)ˆk
40
```
A vector of magnitude 5 CANNOT be added to a vector of magnitude 8 so that the magnitude of the resultant is:
A) 2
B) 4
C) 9
D) 10
E) 13
```
A) 3
41
```
The airplane shown is in level flight at an altitude of 0.50 km and a speed of 150 km/h. At what distance d should it release a heavy bomb to hit the target X? Assume the bomb falls without any effect from air resistance and take g= 10 m/s2.
A) 150 m
B) 295 m
C) 417 m
D) 2550 m
E) 15,000 m
```
C) 417
42
```
A ball is thrown horizontally from the top of a 50 m high hill. It strikes the ground at an angle of 40◦.With approximately what initial speed was it thrown?
A) 37 m/s
B) 55 m/s
C) 64 m/s
D) 79 m/s
E) 84 m/s
```
A) 37 m/s
43
```
A stone is thrown outward from the top of a 45.0 m high cliff with an upward velocity component of14.0 m/s. How long is stone in the air before it hits the ground at the bottom of the cliff?
A) 4.78 s
B) 5.21 s
C) 6.10 s
D) 7.33 s
E) 8.15 s
```
A)4.78 s
44
```
A canon fires a projectile as shown. The dashed line shows the trajectory in the absence of gravity;points MNOP correspond to the position of the projectile at two second intervals. If g= 10 m/s2, the lengths X,Y,Z are:
A) 8 m, 32 m, 96 m
B) 10 m, 20 m, 45 m
C) 16 m, 40 m, 90 m
D) 20 m, 40 m, 120 m
E) 20 m, 80 m, 180 m
```
E) 20m, 80 m, 180 m
45
```
A stone is tied to a 0.70 m string and whirled at a constant speed of 4.5 m/s in a vertical circle. Its acceleration at the top of the circle is:
A) 24 m/s2, up
B) 24 m/s2, down
C) 29 m/s2, up
D) 29 m/s2, down
E) 32 m/s2, down
```
D) 29 m/s^2, down
46
```
A car rounds a 200 m radius curve at 20 m/s. The magnitude of its acceleration is:
A) 0.14 m/s2
B) 0.20 m/s2
C) 2.0 m/s2
D) 4.0 m/s2
E) 8 m/s2
```
C) 2.0 m/s^2
47
```
A boy wishes to row across a river in the shortest possible time. He can row at 2 m/s in still water andthe river is flowing at 1 m/s. At what angleθshould he point the bow (front) of his boat?
A) 30◦
B) 45◦
C) 60◦
D) 63◦
E) 90◦
```
E) 90◦
