8. When a problem has multiple frames of reference, is used to determine relative velocity. a. magnitude c. vector addition b. multiplication d. algebra Answer the following questions. Show your calculations. You may find a diagram helpful in answering the questions. 1. A punter kicks a football at an angle of 45 to the ground. The football has an initial velocity of 25 m/s. a. How long is the football in the air? b . How far does the football travel horizontally? C. What is the maximum height of the football? 2. A car moving at 30.0 km/h rounds a bend in the road that has a radius of 21.2 m. What is the centripetal acceleration of the car?Applying Physics Knowledge Answer thefollowiug questions. Show your calculations. 1. A remote-control car with a constant velocity drives off the top of a wall that is 10.0 In high and lands 4.60 m from the base of the wall. a. Draw a diagram of the problem. Label the known and unknown quantities. b. What is the car's speed before it drives off the top of the wall? Name d. How far from the base of the wall would the remote-control car have landed if it had been subject to the gravitational eld on the Moon (1.7r kag)? J. A boat moves north at a speed of 2. / m/s across a river that flows west at a rate Of 1.2 m/s. what is the boat's speed relative to the riverbank? 0 Thinking Critically Refer to the graphs to answer questions 1-5. Use complete sentences. Graph A Graph B Position Position Time Time 1. The graphs above show position versus time for the first half of a projectile's flight. Which graph shows horizontal position and which shows vertical position? How do you know? 2. What do the slopes of the graphs represent? 3. What would a line graph of vertical velocity versus time look like?MOTION IN TWO DIMENSIONS Understanding Physics Concepts Circle the letter of the choice that best completes the statement or answers the question. 1. The horizontal and vertical components of a projectile's velocity are a. directly proportional c. independent of each other b. inversely proportional d. equal 2. A projectile's horizontal acceleration after that projectile is fired is a. dependent on the vertical acceleration b. directly proportional to the free-fall acceleration C. constant e zero 3. Neglecting air resistance, the initial horizontal velocity of a projectile is its final horizontal velocity. a. greater than c. equal to b. less than d. directly proportional to 4. For a receiver to catch a football at chest level, the quarterback must aim the football the receiver's chest. a. directly at c. below b. above d. to the side of 5. How far does an object in uniform circular motion travel during one period? a. 2p, c. v/r a b. d. 6. An object in uniform circular motion has an acceleration that is . in a direction tangential to the circle h. toward the center of the circle4. What would a line graph of horizontal velocity versus time look like? 5. At what point on the position-time graph does the projectile have its maximum vertical speed? At what point does it have its minimum vertical speed? 0 Answer the following questions. Show your calculations. 6. A 0.150-kg rubber stopper is attached to the end of a 1.00-m string and is swung in a circle. a. If the stopper makes 0.85 rev/s, what is the force the string exerts on the stopper? b. If the rubber stopper is swung 2.3 m above the ground and released, how far will the stopper travel horizontally before hitting the ground?2. An 82.0-kg person rides on a carnival ride in a 45.0-kg basket supported by a single chain. When the ride reaches its top speed, the basket moves at a constant speed in a horizontal circle with a radius of 7. 10 m. At this point, the chain supporting the basket is at a 45.0[| angle to the vertical. You may want to draw a diagram to help you answer the questions. a. At top speed, how large are the vertical and horizontal components of the tension in the chain? (Hint: The vertical component of the tension equals the weight it supports.) b. What is the magnitude of the centripetal acceleration of the basket and its passenger? c. What is the speed of the basket and its passenger? d. How long does it take the basket to make one complete circle?I 3. Lois and Leo are riding their unicycles side by side. They are heading east at a Speed of3.5 mfs. Lois tosses a large beach ball over to Leo with a velocity of 0.76 mx's north. What is the velocity of the beach ball relative to the ground