Vivian is walking to the hairdresser’s at 1.3 m/s when she glances at her
watch and realizes that she is going to be late for her appointment. Vivian
gradually quickens her pace at a rate of 0.090 m/s2.
a. What is Vivian’s speed after 10.0s?
b. At this speed, is Vivian walking, jogging, or running very fast?
Vivian is walking to the hairdresser’s at 1.3 m/s when she glances at her
watch and realizes that she is going to be late for her appointment. Vivian
gradually quickens her pace at a rate of 0.090 m/s2.
a. What is Vivian’s speed after 10.0s?
b. At this speed, is Vivian walking, jogging, or running very fast?
3. A jumbo jet taxiing down the runway receives word that it must return to the
gate to pick up an important passenger who was late to his connecting flight.
The jet is traveling at 45.0 m/s when the pilot receives the message. What is the
acceleration of the plane if it takes the pilot 5.00 s to bring the plane to a halt?
v = Vi + a t = 1.3 + 0.090 * 10 = 1.3 + 0.9 = 2.2 meters/second
100 meters would take her 45 seconds. How long does it take you to jog the length of a football field?
same thing for the plane
v = Vi + a t
0 = 45 - 5 t
t = 45/5 = 9 seconds
To find the answers, we need to use the equations of motion. The first equation of motion is:
v = u + at
Where:
v = final velocity
u = initial velocity
a = acceleration
t = time
a) Let's find Vivian's speed after 10.0s. We know her initial velocity (u) is 1.3 m/s, the acceleration (a) is 0.090 m/s², and the time (t) is 10.0s. Plugging in these values into the equation, we get:
v = 1.3 m/s + (0.090 m/s²) * 10.0s
v = 1.3 m/s + 0.9 m/s
v = 2.2 m/s
So, Vivian's speed after 10.0s is 2.2 m/s.
b) Now, to determine if Vivian is walking, jogging, or running very fast at this speed, we can make some general classifications:
- Walking speeds typically range from 0.8 m/s to 1.3 m/s.
- Jogging speeds typically range from 1.3 m/s to 2.7 m/s.
- Running speeds usually exceed 2.7 m/s.
Based on these classifications, Vivian's speed of 2.2 m/s falls within the jogging range. Therefore, at this speed, Vivian is jogging.