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Page 2 PHY 201 Test 3VersionB Spring 2018 Multiple Choice Questions: (10 Points

ID: 2040256 • Letter: P

Question

Page 2 PHY 201 Test 3VersionB Spring 2018 Multiple Choice Questions: (10 Points Each) Choose the correct answer of the following and show your work to get full credit 1. An object is moving at a constant rate in a horizontal circular path of radius 1 m. If the rad acceleration of the object is 625 m/s, its speed is: a. 625 m/s b. 25 m/s c. 5 m/s d. 1 m/s 2 In the formula the quantity G: a. is greatest at the surface of the Earth b. depends on the local value of g c. is a universal constant of nature d. is related to the Sun in the same way that g is related to the Earth 3. If you walk 10 m along a horizontal floor while holding a 50-kg box on your hand, ho work you do on the box? a) Zero b) 4900 J c) 490 J d) 49 J 4. An object moving with a speed of 10 m/s has a kinetic energy of 200 J. Mass of t is: a. 1 kg b. 2 kg C. 4 kg d. 10 kg

Explanation / Answer

1) b) 25 m/s

use, a_rad = v^2/r

==> v = sqrt(a_rad*r)

= sqrt(625*1)

= 25 m/s


2) c) is a universal cinstant of nature

3) a) zero

W = F*d*cos(theta)

= m*g*d*cos(90)

= 0

4) c) 4 kg

KE = (1/2)*m*v^2

==> m = 2*KE/v^2

= 2*200/10^2

= 4 kg