110 likes | 209 Views
Physics Concepts and Connections. Quiz 2. INSTRUCTOR: TAO LIN SHANDONG UNIVERSITY , WEIHAI Autumn 2011. 1. A particle’s position in meters is described by the equations x=1-2t+3t 2 y=2+t-t 2 What is the magnitude of the particle’s displacement at t=3 seconds?. A. 22.4 m B. 18.4 m
E N D
Physics Concepts and Connections Quiz 2 INSTRUCTOR: TAO LIN SHANDONG UNIVERSITY , WEIHAI Autumn 2011
1. A particle’s position in meters is described by the equationsx=1-2t+3t2y=2+t-t2What is the magnitude of the particle’s displacement at t=3 seconds? A. 22.4 m B. 18.4 m C. 14.2 m D. 12.2 m
2. A particle’s position in meters is described by the equationsx=1-2t+3t2y=2+t-t2What is the magnitude of the particle’s velocity at t=3 seconds? A. 20.7 m/s B. 16.8 m/s C. 11.0 m/s D. 8.1 m/s
3. A particle’s position in meters is described by the equationsx=1-2t+3t2y=2+t-t2What is the magnitude of the particle’s acceleration? A. 2.1 m/s2 B. 3.2 m/s2 C. 4.4 m/s2 D. 6.3 m/s2
4. A particle is fired with some initial velocity v0 at an angle of 35° above the horizontal. If the time of flight is 10 seconds, and the range is 15 meters, what is v0? A. 1.8 m/s B. 2.6 m/s C. 1.5 m/s D. 3.5 m/s x = x0 + v0xt y = y0 + v0yt – ½gt2 vx = v0x vy = v0y – gt
5. Which projectiles have similar ranges? The magnitudes are the same, and angles between adjacent vectors are all 15°. A. A and B; D and E B. A and D; B and E C. A and E; B and D D. A and E; B, C, and D E R = 2 v02 sinθ cosθ / g D C B A
6. These equations are valid for accelerations that are constant or for those that depend on position, but not for those that depend on time. A. True B. False x = x0 + v0t + ½at2v = v0 + at
7. A car undergoes a constant acceleration of 0.5 m/s2. If it starts from rest, how much distance is covered by the time it is traveling 30 m/s? A. 225 m B. 450 m C. 900 m D. 3000 m x = x0 + v0t + ½at2v = v0 + at
8. A particle has a velocity (in m/s) in the x-direction of vx = 1-2t+t2. What is its acceleration, and in what direction, does it have at t = 2 seconds? + denotes to the right. A. 1 m/s2 to the right B. 2 m/s2 to the right C. 1.333 m/s2 to the left D. 3 m/s2 to the left Note: Modified from what was given in class.
9. An object is dropped (from rest) off of a 30 m roof. How fast is it traveling when it hits the ground? Take g = -9.8m/s2 A. -13.1 m/s B. -17.1 m/s C. -24.2 m/s D. -30 m/s E. -294 m/s x = x0 + v0t + ½at2v = v0 + at
10. What magnitude of acceleration do you need in order to bring an object that is traveling 10 m/s to rest in 3 m? Does this exceed 1 g (9.8m/s2)? A. 16.7 m/s2, Yes B. 33.3 m/s2, Yes C. 7.2 m/s2, No D. 18.1 m/s2, Yes E. 0.3 m/s2, No x = x0 + v0t + ½at2v = v0 + at