# Conceptual Physics 10th Ed. Ch 3.

## 26 terms · Linear motion - Motion is relative

### Speed = distance/time km/s

Formula for Speed

### Average speed = total distance covered/time interval (320 km/4h = 80 km)

Formula for Average speed

### 20 km/h = 6 m/s

12 mi/h = ? km/h =? m/s

### Velocity

The speed of an object and the specification of its direction.

### vector force

Velocity is also considered a

### Constant Velocity

Constant speed with constant direction is called

### acceleration

How quickly velocity changes is called

### Acceleration = change in velocity/time interval

Formula for acceleration

### Velocity acquired = acceleration x time

Formula for velocity acquired

### Freefall

motion under the influence of gravity alone

10 m/s squared

### v = g x t (g = 10)

formula for velocity of a falling object is

### d = 1/2 gt^2

formula for distance of falling objects is

### d = (Vi + Vf/2) x t

if object is thrown, formula for distance is

### t = (square root of 2d/a) a=g=10m/s^2

Formula for for hang time

### Vector quantity

Quantity in physics that has both magnitude and direction

### The horses speed is 30 km/h (formula is d = 15 speed/time (0.5)

What is the average speed in kilometers per hour for a horse that gallops a distance of 15 km in a time of 30 min?

### Yes the car moves at a constant speed.

If a car moves at constant velocity, does it also move at a constant speed?

### Yes it maintains constant speed, but no it does not maintain a constant velocity because a constant velocity is both constant speed and constant direction.

If a car is moving at 90 km/h and it rounds a corner, also at 90 km/h, does it maintain a constant speed? A constant velocity? Defend your answer?

### 10 km/h/s

What is the acceleration of a car that increases its velocity from 0 to 100 km/h in 10 s?

### The acceleration is 0 because the car maintains constant velocity.

What is the acceleration of a car that maintains a constant velocity of 100 km/h for 10 s?

### the gain is g which is 10m/s^2

What is the gain in speed per second for a freely falling object?

### v = gt velocity is 50m/s, 60 m/s

What is the velocity acquired by a freely falling object 5s after it is dropped from a rest position? What is it 6 s after?

### the object loses g, 10m/s

When an object is thrown upward, how much speed does it lose each seconf?

### d = 1/2gt^2, After 1 second 5m, after 4 s 80m

What is the distance fallen for a freely falling object 1 s after being dropped from a rest position? What is it 4 s after?

### An example is a car slowing down.

Can you cite an example in which the acceleration of a body is opposite in direction to its velocity? if so, what is your example?