Earth pulls it downward to the gravitational force
Your position in meters will, measured relative to the starting point of the car behind you, be
x1(t) = 10 + 23.61 t - 1/2 4.2 t^2
his position will be
x2(t) = 16.67 t
Hence at any time the separation s(t) will be
s(t) = x1(t) - x2(t) = 10 + 6.94 t -2.1 t^2
Now I assume you mean that you will decelerate UNTIl you are driving at the legal speed limit (60 km/h). That will take you:
16.67 m/s = 23.61m/s - 4.2 m/s^2 * t
t = 1.65 seconds
What is the separation at that time? If it is still greater than zero, there will be no collision:
s(1.65) = 10 + 6.94 *1.65 -2.1 (1.65)^2 = 15.73 meters.
Hence you will NOT collide. The 1.65 s you calculated was the time needed to brake to the speed of 60 km/h.
Answer:
<h2>320</h2>
Just use F =ma where m is mass and a is acc.
<span>v² = u² + 2as </span>
2as = v² - u²
<span>a = (v² - u²) / 2s </span>
<span>a = (20.0² m²/s² - 6.00² m²/s²) / (2 * 50.0 m) </span>
<span>a = (400 m²/s² - 36 m²/s²) / (100 m) </span>
<span>a = (364 m²/s²) / (100 m) </span>
a = 3.64 m/s²