ACE Physics 1134 PACE Test

5 things Galileo Galilei discovered with his telescope

1.) mountains and craters on the moon 2.) Venus has phases like the moon 3.) four large moons of Jupiter 4.) dark spots on the sun 5.) thousands of additional stars in the Milky Way

State Newton's third law of motion

When any two bodies interact, the force exerted by the first body on the second is equal and opposite to the force exerted by the second body on the first.

Why is Kepler's third law of planetary motion so helpful to astronomers?

With the third law, astronomers could calculate the distance of the planets form the sun.

Gravity between two objects is directly proportional to the

product of their masses

The same truck comes to a stop in 4.0 seconds. Find the acceleration

0 m/sec - 16.67 m/sec = -16.67 m/sec. -16.67 m/sec divided by 4 seconds = -4.2 m/sec^2

A truck starts form rest and accelerates to 60 kilometers per hour in 15 seconds. Find the acceleration of the truck.

60 km/h - 0 km/h divided by 15 seconds. You need to convert the kilometers per second to meters per second by multiplying 60 X 1000 = 60,000 meters. Convert hours by multiplying 60 X 60 = 3600 seconds. Divide 60,000 by 3600 to get 16.67. Divide 16.67 by 15. The answer is 1.1 m/sec^2

State Kepler's second law of planetary motion

A planet sweeps out equal areas in equal intervals of time as it orbits the sun.

State Kepler's first law of planetary motion

Each planet moves about the sun in an elliptical orbit; the sun is at one focus of the ellipse

State Newton's first law of motion

Every body continues in its state of rest, or of uniform motion in a straight line, unless it is compelled to change that state by forces impressed upon it

What happens to the velocity of a planet when it orbits closer to the sun?

It's velocity increases.

State Newton's second law of motion

The acceleration of a body is directly proportional to the resultant force acting on that body and inversely proportional to the mass of the body.

State Kepler's third law of planetary motion.

The square of a planet's period is directly proportional to the cube of its distance from the sun.

What is dynamics?

The study of the causes for change in motion

Right and wrong are determined by

absolutes found in the Bible.

two forces that are directly related

acceleration and force

found by multiplying the final velocity times one half

average velocity

To find acceleration

divide change in velocity by change in time

Into what two components can a projectile's motion be resolved?

horizontal and vertical

Greek beliefs were based on

human reasoning

Three divisions of mechanics

kinetics, dynamics, and statics

two forces that are inversely related

mass and acceleration

If the launch velocity and angle of the projectile are known, what three quantities can be calculated?

maximum height, range, time of flight

A projectile follows a path called a

parabola

A swimmer jumps from a cliff and enters the water 1.75 seconds later. How high is the cliff?

s = 1/2 X g X t^2 s = 1/2 X 9.81 m/sec^2 X (1.75)^2 = s = 1/2 X 9.81 m/sec^2 X 3.0625 = 15.0 m

Velocity is a vector composed of

speed and direction

Gravity between two objects is inversely proportional to the

square of the distance between their centers of mass

A body falls freely for 17.0 seconds. Given that g = 9.81 m/sec^2, calculate the final velocity, average velocity, and the distance the body falls.

v = g X t v = 9.81 m/sec^2 X 17 sec = 167 m/sec (final velocity) v = 0.5 X the final velocity v = 0.5 X 167 = 83.5 m/sec (average velocity) v = average velocity X t v = 83.5 X 17 = 1420 m (distance the body falls)

A cannonball is fired with a muzzle velocity of 100 m/sec at exactly 40 degrees. Calculate the initial vertical velocity, initial horizontal velocity, maximum height reached, time of flight, and range.

vertical velocity: 100 m/sec X the sin of 40 degrees 100 m/sec X 0.643 = 64.3 m/sec Horizontal velocity: 100 m/sec X the cosine of 40 degrees 100 m/sec X 0.766 = 76.6 m/sec time of flight: 2 X vertical velocity / g 2 X 64.3 m/sec / 9.81 m/sec^2 = 13.1 sec range: cosine of 40 degrees X t 76.6 m/sec X 13.1 sec = 1003 m maximum height reached: 1/2 X vertical velocity X vertical velocity/g 1/2 X 64.3 m/sec X 64.3 m/sec/ 9.81 m/sec^2 = 211 m