Practice Questions Page 228
Solutions
Q1.
Given: 𝑎𝑐 = 3.0 m⁄s 2 , and r = 2.1 m
𝑎𝑐 =
𝑉𝑡2
𝑟
2
𝑉𝑡2 = 𝑎𝑐 × 𝑟 = 3.0 m⁄s 2 × 2.1𝑚 = 6.3 m ⁄s 2
2
𝑉𝑡 = √6.3 m ⁄s 2 = 𝟐. 𝟓𝟎𝟗 𝐦/𝐬
Q2.
Given: 𝑎𝑐 = 250 m⁄ 2 , and r = 0.5 m.
s
𝑎𝑐 =
𝑉𝑡2
𝑟
2
𝑉𝑡2 = 𝑎𝑐 × 𝑟 = 250 m⁄s 2 × 0.5m = 125 m ⁄s 2
2
𝑉𝑡 = √125 m ⁄s 2 = 𝟏𝟏. 𝟏𝟖 𝐦/𝐬
Q3.
Given: 𝑉𝑡 = 7.85 m⁄s , and r = 20 m.
𝑎𝑐 =
𝑉𝑡2
𝑟
=
(7.85 m⁄s)2
20 𝑚
= 3.08 m⁄s 2
Q4.
Given: 𝑎𝑐 = 0.29 m⁄s 2 and 𝑉𝑡 = 0.17 m⁄s
𝑎𝑐 =
𝑉𝑡2
𝑟
𝑜𝑟 𝑟 =
𝑉𝑡2
𝑎𝑐
=
(0.17 m⁄s)2
0.29 m⁄ 2
s
(0.17 m⁄s)2
𝑟=
= 0.099 𝑚
0.29 m⁄ 2
s