<span>Since forces are vector quantities, we must indicate direction using positive and negative values. East will be assigned positive and west will be negative. Friction will act as a negative force since it impedes action. To calculate the net force we sum the vector quantities, as follows. Net force equals 50n which is derived by the following calculation: 300n-220n-30n.</span>
Answer:
Vf = 2000 [m/s]
Explanation:
To solve this problem we must use the following equation of kinematics.
where:
Vf = final velocity [m/s]
Vo = initial velocity = 1200 [m/s]
a = acceleration = 4 [m/s]
t = 200 [s]
Vf = 1200 + (4*200)
Vf = 1200 + 800
Vf = 2000 [m/s]
Work = Force * distance
Work = 40N * 10m
Work = 400N
<span>We know that v = u + at
He stops when the speed is zero; therefore
0 = 15 - 3.35 t
t = 4.48
It takes 4.48 seconds after the driver turns on the brake for him to stop.
We know
s = ut + (1/2)at</span>²<span>
s = 15*4.48 - *(1/2)(3.25)(4.48)</span>²<span>
s = 33.4 meters
The distance he travels before applying the brakes is:
s = 0.21 * 15
s = 3.15 m
The total distance he travels is:
3.15 + </span>33.4 = 36.55 meters
He will be able to stop in time.
Here is a picture of my work. It's easier than typing it out!