Physics #4

Total Flash Cards » 21
 
1. 

According to Kepler's laws, the planets orbit the Sun along the paths that are

 

ELLIPSES

 
2. 

A rock is trown upward at an angle of 50 degrees with respect to the horizontal. As it rises, neglecting air resistance, the vertical component of its velocity

 

DECREASES

 
3. 

A ball is thrown upward at 50 degrees with respect to the horizontal. As it rises, neglecting air resistance, the horizontal component of its velocity

 

DOES NOT CHANGE

 
4. 

A stone is thrown horizontally from the top of a cliff. One second after it has left your hand, its vertical distance below the top of the cliff is

 

5 M

 
5. 

A bullet fired horizontally from a rifle begins to fall

 

AS SOON AS IT LEAVES THE BARREL

 
6. 

A projectile is launched vertically upward at 50 m/s.If air resistance is negligible, its speed upon returning to its starting point is

 

EXACTLY 50 M/S

 
7. 

An Earth satellite is simply a projectile

 

FREELY FALLING AROUND THE EARTH

 
8. 

A hunter on level ground fires a bullet at zero-degree angle with the horizontal while simultaneously dropping another bullet from the level of the rifle. Which bullet will hit the ground first?

 

BOTH HIT THE GROUND AT THE SAME TIME

 
9. 

An object is dropped and freely falls to the ground with an acceleration of 1g. If it is thrown upward at an angle instead, its acceleration will be

 

1G DOWNWARD

 
10. 

Two projectiles are fired from ground level at equal speeds but different angles. One is fired at an angle of 30 degrees and the other at 60 degrees. Neglecting air resistance, the projectile to hit the ground first will be the one fired at

 

30 DEGREES

 
11. 

A projectile is fired vertically from the surface of the Earth at 8 km/s. The projectile will

 

RISE AND FALL BACK TO THE EARTH'S SURFACE

 
12. 

An object is thrown vertically into the air. Because of air resistance, the time for its descent will be

 

LONGER THAN THE ASCENT TIME

 
13. 

A river 100 yards wide flows due South at 1 yard per second. A boat that goes at one yard per second relative to the water is pointed due East as it crosses from the West bank. The boat reaches the East bank

 

100 YARDS FARTHER SOUTH THAN WHERE IT STARTED

 
14. 

What prevents satellites such as the space shuttle from falling?

 

NOTHING: THEY ARE CONTINUALLY FALLING AS THEY ORBIT THE EARTH

 
15. 

The fastest moving planet in a solar system is

 

THE PLANET NEAREST TO THE SUN

 
16. 

A person on the surface of the Earth has a mass of 50 kg and a weight of 490 N. If this person were floating freely inside a space station far away from Earth, she or he would have

 

LESS WEIGHT AND THE SAME MASS

 
17. 

Consider a moon that orbits one of our most distant planets in an elliptical path. The distance that the moon covers each day is

 

GREATEST WHEN THE MOON IS CLOSEST TO THE PLANET

 
18. 

The speeds of the planets about the Sun depend on

 

THEIR DISTANCE FROM THE SUN

 
19. 

The Early Bird communication satellite hovers over the same point on Earth's equator indefinitely. This is because

 

ITS ORBITAL PERIOD IS 24 HOURS

 
20. 

Angular momentum is greater for a satellite when it is at the

 

ITS ANGULAR MOMENTUM IS THE SAME AT ANY POINT ON ITS TRACETORY

 
21. 

A weightless astronaut in an orbiting shuttle is

 

LIKE THE SHUTTLE, PULLED BY EARTH'S GRAVITATION