Download presentation

Presentation is loading. Please wait.

Published byTimothy George Modified over 4 years ago

1
All quantities in Physics can be categorized as either a scalar or a vector quantity. A scalar quantity has magnitude (amount) only without direction. Ex. 4 meters, 3 seconds. A vector quantity has magnitude with direction. Ex 4 meters North, 5 Newtons East. note: the units for force are Newtons (N) A vector is drawn as an arrow to indicate direction and a length proportional to the quantity. Ex. 6 Meters East The length of this arrow is 6 cm s the scale would be 1 m = 1 cm. Distance is the length the object travels. Displacement is the length with direction from the beginning of the journey to the end in a straight line. Ex. A student walks 5 meters east and then 12 meters North Distance = 17 meters Displacement = 13 m @ 67° N of E (using geometry.

2
The distance a body moves per unit of time is called speed. There is instantaneous speed, average speed, and final speed. Velocity is a vector quantity of speed with direction. v = Δ d/ Δ t ex: How fast is a car moving if it goes 30 meters in 5 seconds? v = Δ d/ Δ t v = 30 m / 5 s v = 6 m/s Average velocity is the sum of the initial velocity and final velocity divided by 2. It is also the total distance traveled divided by the total time elapsed. Ave v = (v f + v i )/2 Or Ave v = Δ d/ Δ t Acceleration is the rate of change of velocity per unit of time. a = Δv/ Δ t What is the acceleration of a ball rolling from rest down a hill to a speed of 16 m/s in 8 seconds? a = Δv/ Δ t a = (16m/s – 0 m/s)/ 8s a = 2 m/s 2

3
You can calculate the distance traveled with a constant acceleration for the previous example using this formula; d = v i Δ t + ½ a Δ t 2 d = v i Δ t + ½ a Δ t 2 d = (0m/s)(8s) + ½ 2 m/s 2 (8s) 2 64 m We can also calculate how fast the ball is going when it reaches the end of the hill if we were not given it. v f = v i + at v f = 0 m/s + (2 m/s 2 ) (8s) v f = 16 m/s note: the units (m/s 2 )(s) gives you m/s If you are given the time use this formula. If you are not given time but you have the distance use the next one. or v f 2 = v i 2 + 2ad v f 2 = (0 m/s) 2 + 2(2m/s 2 )(64m) v f 2 = √256 m 2 /s 2 v f = 16 m/s

Similar presentations

© 2020 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google