A 1543.1 kg car is traveling at 25.1 m/s when
the driver takes his foot off the gas pedal. It
takes 5.7 s for the car to slow down to 20 m/s.
How large is the net force slowing the car?
Answer in units of N
V = Vo + a*t
V = 20 m/s.
Vo = 25.1 m/s.
t = 5.7 s.
Solve for a. (It should be negative.)
F = M*a
To find the net force slowing the car down, we can use Newton's second law of motion:
F = m * a
Where F is the net force, m is the mass of the car, and a is the acceleration.
First, let's find the acceleration of the car. We can use the equation of motion:
(vf - vi) = a * t
Where vf is the final velocity, vi is the initial velocity, a is the acceleration, and t is the time taken.
Rearranging the equation to find the acceleration:
a = (vf - vi) / t
Substituting the given values:
vf = 20 m/s
vi = 25.1 m/s
t = 5.7 s
a = (20 - 25.1) / 5.7
a ≈ -0.8947 m/s² (negative sign indicates deceleration)
Now, we can calculate the net force:
F = m * a
Substituting the given mass:
m = 1543.1 kg
F = 1543.1 kg * -0.8947 m/s²
F ≈ -1380.45 N
The net force slowing the car down is approximately -1380.45 N. The negative sign indicates that the force is in the opposite direction of the car's motion.