Question 1

In the game of tetherball, the ball moves in a horizontal circle around the pole. In what direction does the net force on the ball point?

Accepted Answer

Along the horizontal component of the tension force

Question 2

A passenger in a car (not wearing a seatbelt) feels as if they are thrown to the right during a sharp left turn. What is actually happening from a physics perspective?

Accepted Answer

The door is exerting a leftward force on you

Question 3

You drive too fast around a curve and your car starts to skid. What is the correct explanation for this situation?

Accepted Answer

Friction between tires and road is not strong enough to keep car in a circle

Question 4

A ping pong ball is shot into a circular tube lying flat on a table. When the ball leaves the tube, which path will it follow?

Accepted Answer

It will continue in a straight line tangent to the circle

Question 5

Two equal-mass rocks are whirled in horizontal circles on strings. The radius of circle 2 is twice that of circle 1, and the period is the same for both. What is the tension in cord 2 compared to cord 1?

Accepted Answer

$$T_2 = 2$$ $$T_1$$

Question 6

A rider in a 'barrel of fun' amusement ride is stuck with her back to the wall as the barrel spins. Which force provides the centripetal force keeping her in circular motion?

Accepted Answer

Normal force from the wall

Question 7

You’re on a Ferris wheel moving in a vertical circle. At the top of the Ferris wheel, how does the normal force $$N$$ exerted by your seat compare to your weight $$mg$$?

Accepted Answer

$$N is $$smaller than $$mg$$

Question 8

A skier goes over a small round hill of radius $$R. At $$the top of the hill, what is the centripetal force $$F_c$$ equal to?

Accepted Answer

$$F_c = mg - N$$

Question 9

You swing a ball at the end of a string in a vertical circle. At the top of the ball’s path, what is the centripetal force $$F_c$$ equal to?

Accepted Answer

$$F_c = T + mg$$

Question 10

Which is stronger: Earth’s pull on the Moon, or the Moon’s pull on Earth?

Accepted Answer

They pull on each other equally

Question 11

If the distance to the Moon were doubled, then the force of attraction between Earth and the Moon would be:

Accepted Answer

One quarter

Question 12

You weigh yourself on a scale inside an airplane flying at constant speed at an altitude of 20,000 feet. How does your measured weight compare with your weight on the surface of the Earth?

Accepted Answer

Less than

Question 13

Two satellites A and B of the same mass orbit Earth in concentric orbits. The distance of satellite B from Earth’s center is twice that of satellite A. What is the ratio of the centripetal force acting on B compared to A?

Accepted Answer

$$\frac{1}{4}$$

Question 14

The Moon does not crash into Earth because:

Accepted Answer

It has sufficient speed to stay in orbit due to gravity providing the centripetal force

Question 15

Astronauts in the space shuttle float because:

Accepted Answer

While gravity is trying to pull them inward, they are trying to continue on a straight-line path

Question 16

If you weigh yourself at the equator of Earth, would you get a bigger, smaller, or similar value than if you weigh yourself at one of the poles?

Accepted Answer

Smaller value

Question 17

A planet of mass $$m is a $$distance $$d$$ from Earth. Another planet of mass $$2m is a $$distance $$2d$$ from Earth. Which force vector best represents the direction of the total gravitational force on Earth?

Accepted Answer

The force due to $$m is $$greater, so the net force points more toward $$m$$ than $$2m$$

Question 18

A satellite is orbiting Earth. What happens if it slows down due to atmospheric drag?

Accepted Answer

It will spiral inward toward Earth

Question 19

What physical force provides the centripetal force for a car turning on a flat road?

Accepted Answer

Friction between the tires and the road

Physics: Principles with Applications – Chapter 5 Study Guidance

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드