Jump-start Problem 4 Name:
Phys 213 Spring 2025
Ray is driving his car along a straight section of road at a constant velocity to the right. Upon
noticing a pedestrian crossing ahead, he applies the brakes, to give the car a constant acceleration
of 2.55 m/s2to the left. After 9.00 seconds of braking, his velocity reduces to 1.40 m/s.
a) What was the car’s velocity when Ray first applied the brakes?
ωv0=
b) What is his velocity after traveling a distance of 20.0 m from the moment he applies the
brakes?
ωv=
Genesis Graves
24
.
35 ms
at
j
1
.
48
0
(2
.
55)(9
.
00)
1
.
40
o
22
.
95
o
24
.
35ms
~
22
.
16
2
2
D
Lad
124
.
35(22)2
.
55)(20
.
0)
593
.
12
102
491
.
12
~
22
.
16 ms
