Fisica

Chapter 6
Circular Motion and Other Applications of Newton’s Law

Multiple Choice

1. A race car travels 40 m/s around a banked (45( with the horizontal) circular (radius = 0.20 km) track. What is the magnitude of the resultant force on the 80-kg driver of this car?

a. 0.68 kN b.0.64 kN c.0.72 kN d.0.76 kN e.0.52 kN
2. An airplane travels 80 m/s as it makes a horizontal circular turnwhich has a 0.80-km radius. What is the magnitude of the resultant force on the 75-kg pilot of this airplane?

a. 0.69 kN b.0.63 kN c.0.66 kN d.0.60 kN e.0.57 kN
3. An airplane moves 140 m/s as it travels around a vertical circular loop which has a 1.0-km radius. What is the magnitude of the resultant force on the 70-kg pilot of this plane at the bottom of this loop?

a. 2.1 kN b.1.4 kNc.0.69 kN d.1.5 kN e.1.3 kN
4. A car travels along the perimeter of a vertical circle (radius = 0.25 km) at a constant speed of 30 m/s. What is the magnitude of the resultant force on the 60-kg driver of the car at the lowest point on this circular path?

a. 0.37 kN b.0.80 kN c.0.22 kN d.0.59 kN e.0.45 kN
5. A 30-kg child rides on a circus Ferris wheel that takes her around a verticalcircular path with a radius of 20 m every 22 s. What is the magnitude of the resultant force on the child at the highest point on this trajectory?

a. 49 N b.0.29 kN c.0.34 kN d.0.25 kN e.0.76 kN
6. An amusement ride consists of a car moving in a vertical circle on the end of a rigid boom. The radius of the circle is 10 m. The combined weight of the car and riders is 5.0 kN. At the top ofthe circle the car has a speed of 5.0 m/s which is not changing at that instant. What is the force of the boom on the car at the top of the circle?

a. 3.7 kN (Down) b.1.3 kN (Down) c.6.3 kN (Up) d.3.7 kN (Up) e.5.2kN (Down)
7. A highway curve has a radius of 0.14 km and is unbanked. A car weighing 12 kN goes around the curve at a speed of 24 m/s without slipping. What is the magnitude of thehorizontal force of the road on the car?

a. 12 kN b.17 kN c.13 kN d.5.0 kN e.49 kN

8. A 4.0-kg mass on the end of a string rotates in a circular motion on a horizontal frictionless table. The mass has a constant speed of 2.0 m/s and the radius of the circle is 0.80 m. What is the magnitude of the resultant force acting on the mass?

a. 39 N b.20 N c.44 N d.0 N e.30 N

9. Astunt pilot weighing 0.70 kN performs a vertical circular dive of radius 0.80 km. At the bottom of the dive, the pilot has a speed of 0.20 km/s which at that instant is not changing. What force does the plane exert on the pilot?

a. 3.6 kN up b.4.3 kN up c.2.9 kN down d.2.9 kN up e.5.8 kN down

10. A car travels around an unbanked highway curve (radius 0.15 km) at a constant speed of 25 m/s.What is the magnitude of the resultant force acting on the driver, who weighs 0.80 kN?

a. 0.87 kN b.0.34 kN c.0.80 kN d.0.00 kN e.0.67 kN
11. A 0.50-kg mass attached to the end of a string swings in a vertical circle (radius = 2.0 m). When the mass is at the lowest point on the circle, the speed of the mass is 12 m/s. What is the magnitude of the force of the string on the mass at thisposition?

a. 31 N b.36 N c.41 N d.46 N e.23 N
12. A roller-coaster car has a mass of 500 kg when fully loaded with passengers. The car passes over a hill of radius 15 m, as shown. At the top of the hill, the car has a speed of 8.0 m/s. What is the force of the track on the car at the top of the hill?

[pic]

a. 7.0 kN up b.7.0 kN down c.2.8 kN down d.2.8 kN up e.5.6 kN down
13. A0.20-kg object attached to the end of a string swings in a vertical circle (radius = 80 cm). At the top of the circle the speed of the object is 4.5 m/s. What is the magnitude of the tension in the string at this position?
a. 7.0 N b.2.0 N c.3.1 N d.5.1 N e.6.6 N
14. A roller-coaster car has a mass of 500 kg when fully loaded with passengers. At the bottom of a circular dip of radius 40...