Physics MCAT Review Larry Watson 105 Witmer Hall 777-3525 larry_watson@und.nodak.edu Web sites – www.und.nodak.edu/instruct/lwatson/211 – www.und.nodak.edu/instruct/lwatson/212 – www.und.nodak.edu/instruct/lwatson/mcat Goal: Maximize Scores For Success - Reasoning!!! – – – – – meanings, not equations relationships, acceleration/velocity... concepts energy, Newton’s laws, momentum proportional reasoning skills estimation skills Skills are more important than knowledge Know when to move on Test Anxiety Anxiety is a good thing (in moderation) Anxiety Management 101 – Be confident - you CAN do this well – Relaxation techniques • breathe slowly • breathe deeply • focus on the immediate task - forget about previous sections • whatever works Other Hints Read questions before passage find out what you need You may be able to answer some without reading the passage Do not over-complicate the situation interpret the drawings in a straightforward way Review Format Practice, practice, practice – work on skills with sample questions – avoid “comprehensive” review/memorizing Most of physics is energy, momentum, and Newton’s laws-that’s all you need! – look for the similarities in problems Passage II Q 74-81 MCAT 1 Q 76 Starting from a resting position at the left end of the railgun, the armature applies a constant force of 3.0 N to a projectile with a mass of 0.06 kg. How long will it take for the projectile to move 1.0 m? A. 0.02 s B . 0.04 s C . 0.20 s D . 0.40 s Passage II Q 74-81 MCAT 1 Q 78 For a given mass, if the current were decreased by a factor of 2, the exit speed would: A. increase by a factor of 2 B . increase by a factor of 2 C . decrease by a factor of 2 D . decrease by a factor of 2 Passage II Q 74-81 MCAT 1 Q 79 If a projectile leaves a railgun near the surface of Earth with a speed of 2.0 km/s horizontally, how far will it fall in 0.01 s? A. 4.9 x 10-4 m B . 4.9 x 10-2 m C . 9.8 x 10-2 m D . 2.0 x 101 m Passage II Q 74-81 MCAT 1 Q 80 If a projectile with a mass of 0.1 kg accelerates from a resting position to a speed of 10 m/s in 2 sec, what is the average power supplied by the railgun to the projectile? A. 0.5 W B . 2.5 W C . 5.0 W D . 10.0 W No Passage MCAT 1 Q 90 Two charged particles are a distance r apart. If the charges on the two particles and the distance between the particles are doubled, how does the force between the particles change? A. It decreases by a factor of 2. B . It stays the same. C . It increases by a factor of 2. D . It increases by a factor of 8. Passage IV Q 94-99 MCAT 1 Q 96 The glass that is used as a beam splitter is replaced with glass that is identical except that it has a 10% higher index of refraction. Which of the following changes will occur to the pinhole image? A. It will move. B . It will become larger. C . It will become smaller. D . It will become more clear. Passage IV Q 94-99 MCAT 1 Q 97 What is the approximate number of wavelengths of light that can travel in one direction within a retroreflecting bead that has a diameter of 5 x 10-5 m? (Note: The speed of light is 3 x 108 m/s, and its frequency is approximately 1015 Hz.) A. 0.6 B . 1.7 x 102 C . 1.5 x 104 D . 3.3 x 106 Passage IV Q 94-99 MCAT 1 Q 98 If a single-wavelength laser is used in place of the light source and pinhole, how will the image on the viewing screen change? A. It will be larger. B . It will be less bright. C . It will be shifted. D . It will show stronger patterns of interference. Passage IV Q 94-99 MCAT 1 Q 99 With the screen removed, an observer at Point A sees a virtual image of the pinhole. Which of the following indicates that the observer is viewing a virtual image? A. It moves as the observer changes the angle of view. B . It is larger than the real image. C . It is dimmer than the real image. D . It is fuzzier than the real image. No Passage MCAT 1 Q 113 When a downward force is applied at a point 0.06 m to the left of a fulcrum, equilibrium is obtained by placing a mass of 10-7 kg at a point 0.40 m to the right of the fulcrum. What is the magnitude of the downward force? A. 1.5 x 10-7 N B . 6.5 x 10-7 N C . 9.8 x 10-7 N D . 1.5 x 10-6 N No Passage MCAT 1 Q 115 A 0.5 kg ball accelerates from rest at 10 m/s2 for 2 sec. It then collides with and sticks to a 1.0 kg ball that is initially at rest. After the collision, approximately how fast are the balls going? A. 3.3 m/s B . 6.7 m/s C . 10.0 m/s D . 15.0 m/s No Passage MCAT 1 Q 117 A vertically oriented spring is stretched by 0.15 m when a 100 g mass is suspended from it. What is the approximate spring constant of the spring? A. 0.015 N/m B . 0.15 N/m C . 1.5 N/m D . 6.5 N/m Passage X Q 134-138 MCAT 1 Q 135 Which of the following statements as(are) true about the kinetic energy of the projectile when it returns to the elevation from which it was launched? I. It is the same as when as when it was launched. II. It is dependent on the initial velocity. III. It is dependent on the value of p. A. II only B . I and II only C . I and III only D . II and III only Passage X Q 134-138 MCAT 1 Q 136 What is the approximate total energy of the projectile at the highest point in its path? (Note: Assume the the effects of air resistance are negligible.) A. 92 J B . 133 J C . 184 J D . 225 J Passage X Q 134-138 MCAT 1 Q 138 What is the magnitude of the horizontal component of the air resistance on the projectile at any point during flight? (Note: vx = horizontal speed.) A. (pv2)cos 40° B . (pv2)/2 C . (pvx2)sin 40° D . pvx2