ASTB Mechanical Comprehension exam 2023 with 100% correct answers

Which pulleys provide mechanical advantage? - correct answer movable Formula for gear revolutions - correct answer r(revolutions) x d (number of teeth) = R x D Pulley mechanical advantage - correct answer number of parts of the rope that act on the load Note about mechanical advantage: - correct answer mechanical advantage is gained by combining a fixed pulley with a moveable pulley or another fixed pulley of a different diameter What are hydrometers? - correct answer They use floats to measure specific gravity What is specific gravity? - correct answer the weight of a liquid compared with the weight of water. the liquid with the highest specific gravity will cause the float to rise higher in the glass tube The lower the density of the substance... - correct answer ...the farther the hydrometer will sink. first class lever - correct answer fulcrum in the middle (scissors, pliers) second class lever - correct answer fulcrum is at one end, load is in between (nutcracker, wheelbarrow) third class lever - correct answer fulcrum is at one end, effort is in between (tongs, tweezers) Which turns faster? small or big pulley? - correct answer smaller pulley will turn faster than those larger than it. it has to "keep up" and therefore turns faster. mechanical advantage in pistons - correct answer a2 x d2 = a1 x d1 (smaller D)/(bigger D) = mechanical advantage axe is a... - correct answer wedge, which is an inclined plane Fulcrum Resistance Arm Info? - correct answer the farther away the fulcrum is from the resistance arm, the greater the amount of force that is required to lift the weight and the higher the resistance arm will travel Voltimeter? - correct answer Measures total voltage in a circuit Does electricity flow through burnt out bulbs? - correct answer No, but a voltimeter can bypass it if connected on both sides. Series: current and voltage - correct answer current is constant in series, voltage is not Parallel: current and voltage - correct answer voltage is constant, current is not