Use the following information to answer the next two questions.
Two horizontal plates are separated by a distance of 5. 00 em. A beam of electrons
is directed, horizontally, into the region between the plates. The path of the beam is
deflected as shown below. Electrons in the beam have a speed of 9. 00 x 106 m/ s as
they enter the region between the parallel plates. The electric field strength in the
region between the plates is 3.10 x 103 N/C.
Positively charged plate
t_/
2.00cm
Path of--+electron beam
--r---
~OOcm
3.00cm
Negatively charged plate
Note: This diagram is not drawn to scale.
Physics Principles:
I. Uniform motion (balanced forces)
2. Uniformly accelerated motion (unbalanced forces)
3. Circular motion (unbalanced forces)
4. Work-energy theorem
5. Conservation of momentum
6. Conservation of energy
7. Conservation of mass-energy
8. Conservation of charge
9. Conservation of nucleons
I 0. Wave-particle duality
!Numerical Respons~
1267.1
The two physics principles required to determine the horizontal distance travelled by an
electron in the beam in the region between the horizontal plates, in the order of their use
are
and
(Record your two-digit answer in the numerical-response section on the answer sheet)
~68.1 The horizontal distance travelled by an electron in the beam in the region between the
x I o-w m.
horizontal plates, expressed in scientific notation, is
· (Record your three-digit answer in the numerical-response section on the answer sheet)
- I0 I -
Use the following information to answer the next two questions.
A sample of thorium-226 is stored in a lead box, as shown below. Thorium-226 undergoes
alpha decay. The lead box has a small opening on the left side to allow a stream of alpha
particles to escape.
Top-Down View of Apparatus
PathI of alpha particles that exit tbe lead box
Positively
charged plate
I
I
!
Negatively
charged plate
In the sample, a nucleus of thorium-226 is at rest when it undergoes alpha decay. The
daughter nucleus produced, radium-222, has a mass of 3.67 x 10-25 kg and moves to the
right at 3.IO x I0 5 m/s immediately after the decay. The thorium-226 nucleus, the
radium-222 nucleus, and the alpha particle form an isolated system.
To the left of the lead box are two parallel plates, one positively charged and the other
negatively charged, that together produce a uniform electric field. The parallel plates are
2. 00 em apart. The escaping alpha particles are stopped by the electric force just before
they reach the positively charged plate. The complete apparatus is in a vacuum.
Physics Principles:
I. Uniform motion (balanced forces)
2. Uniformly accelerated motion (unbalanced forces)
3. Circular motion (unbalanced forces)
4. Work-energy theorem
5. Conservation of momentum
6. Conservation of energy
7. Conservation of mass-energy
8. Conservation of charge
9. Conservation ofnucleons
I 0. Wave-particle duality
- 102 -
Physics 30 Practice Questions -Answers
1.
A
31.
D
61.
B
2.
D
32.
A
62.
D
3.
2.63
33.
B
63.
c
4.
D
34.
c
64.
215
5.
c
35.
D
65.
B
6.
D
36.
A
66.
c
7.
A
37.
3857
67.
D
8.
A
38.
1.22
68.
A
9.
1804
39.
c
69.
B
10.
B
40.
B
70.
c
11.
2253
41.
D
71.
B
12.
c
42.
D
72.
D
13.
A
43.
B
73.
c
14.
9.09
44.
B
74.
D
15.
13.0
45.
2003
75.
16.
A
46.
A
76.
c
c
17.
4431
47.
77. 3.87
18.
A
48.
c
c
78.
D
19.
2944
49.
D
79.
B
20.
A
50.
B
80.
B
21.
c
51.
A
81.
c';
22.
D
52.
D
82.
B
23.
9505
53.
B
83.
A
24.
D
54.
c
84.
D
25.
D
55.
A
85.
A
26.
D
56.
D
86.
D
27.
D
57.
A
87.
A
28.
c
58.
D
88.
D
29.
A
59.
D
89.
2.75
30.
c
60.
c
90.
c
- I 04-
!Numerical Respons~
~69.1 The two physics principles required to determine the magnitude of the electric force acting
on an alpha particle, in the order of their use are _ _ and _ _ .
(Record your two-digit answer in the numerical-response section on the answer sheet)
~70.1 The magnitude of the electric force acting on an alpha particle, expressed in scientific
notation, is
X
w-w N.
(Record your three-digit answer in the numerical-response section on the answer sheet)
- 103 -
c
153. D
91.
D
92.
4.97
123. A
154.
93.
124. 2323
155. 2.92
94.
c
c
125. A
156. 2.55
95.
D
126. A
157.
96.
3.00
127. A
158. B
97.
1.08
128. B
159. B
98.
2025
129. A
160.
99.
3.72
130. D
161.
100. A
131. A
162.
101. 8.27
132. B
163. D
102. D
133. 7.81
164. A
103. 6.59
134. B
165. B
104. D
135. B
166. B
105. A
136. D
167. B
106. B
137. 1466
168. D
107. 7.83
138. 1.62
169. D
108. A
139. A
170. 9445
109. B
140. D
171. D
c
141. A
172. A
c
173. D
110.
111. A
112.
c
/t22.
142.
143. 1062
c
c
c
c
c
c
174. A
175. A
113. A
144.
I 14. B
145. 6.63
176. A
115. D
146. A
177. 5.5
116. B
147. D
178. B
117. A
148.
c
179. B
118. 2.28
149. D
119. D
150.
c
181. D
120. 3.24
151. D
182. B
121. B
152.
c
183. B
- 105 -
180.
c
246. 1.19
184. 2.73
215. 3321
185. A
216.
c
247. D
186. D
217. B
248. D
187. A
218. D
249. D
188. 24.6
219. D
250. A
189. A
220. 5410
251. 2612
c
221. A
252. B
191. A
222. D
253. 1811
192. 256
223. A
254. A
193. D
224. D
255. B
194. A
225. 3.14
256. 8.85
c
226. D
257. B
196. B
227. A
258. 3014
197. 3.0
228. B
259.
198. 2.55
229. A
260. A
199. B
230. A
261. 21
200. B
231. 8917
262. 8.61
201. 12.5
232. 2.09
263. 42
202. B
233. D
264. 2.11
203. 9237
234. A
265. 57
204. B
235. 18.5
266. 8.33
205. D
236.
206. A
237.
190.
195.
207.
c
c
c
238. 5521
c
208. B
239.
209. D
240. A
210. A
241. A
211.D
242.
212. B
243.
213. B
244. B
c
245. A
214.
c
c
- 106-
c
267. 21
268. 7.71
269. 52 or 54 or 56
270. 4.87