Check Your Understanding

1. Change the velocity or direction of the
2. Acceleration is the rate of change of velocity. Deceleration is also a rate of change of velocity, but where the velocity is lowered.
3. You use the formula of final velocity minus initial velocity to find the rate of change of the velocity.
4. 20 m/s
5. They're both the same direction because acceleration is a change of velocity.
6.

Activity 9.1 B

1.


2.
a)   Δv = vf - vi -- 16 m/s f - 11 m/s f = +5 m/s
b) Δv = vf - vi -- 18 m/s f - 16 m/s f = +2 m/s
c) Δv = vf - vi -- 18 m/s f - 18 m/s f = 0 m/s
d) Δv = vf - vi -- 14 m/s f - 18 m/s f = -4 m/s
e) Δv = vf - vi -- 11 m/s f - 14 m/s f = -3 m/s

What did you find out?

It was gaining speed in the 0-20 second interval and the 20-40 second interval, it was slowing down in the 60-80 second and the 80-100 second intervals, and it was in velocity zero in the 40-60 second interval.

8.1 Check Your Understanding

CLICK HERE

8.1 C and 8.1 D

8.1C


The line did not go through all the dots. This tells me that the lawnmower's motion accelerates and decelerates.


8.1 D Part1



Through 0-6 seconds, there is uniform motion. From 6 - 10 seconds, there is no movement. From 10-12 seconds, there is new uniform motion. Then from 12-16 seconds, there is negative uniform motion before becoming stationary from 16-18 seconds. It then concludes with negative uniform motion once again.

The displacements are:
2mN, 0m, 4mN, 6mS, 0m, 2mS

The slopes are:
Positive, zero, positive, negative, zero, and negative

The total distance is:
16m

8.1 D Part2



(a) The object starts at the origin and travels south
with uniform motion. - 4
(b) The object starts 2 m [S] and travels north
with uniform motion. - 2
(c) The object starts at the origin and travels north
with uniform motion. - 1
(d) The object starts 2 m [N] and travels south
with uniform motion. - 3