Answer:
4.17 m/s²
Explanation:
We are told the reaction time is 0.2 s. Now, during this reaction time the car is going to travel an additional distance of
: x = u × t = 40 × 0.2 = 8 m
where u is the initial velocity of the car which is 40.0 m/s.
We are told that he had 200 m to stop before applying brakes. Thus, after applying brakes, he now has a distance to cover of; s = 200 - 8 = 192 m
Since vehicle is coming to rest acceleration would be negative, thus using Newton's equation of motion, we have;
v
² = u² - 2as
v = 0 m/s since it's coming to rest
u = 40 m/s
s = 192 m
Thus;
0² = 40² - 2(a)(192)
0² = 1600 - 384a
a = 1600/384
a = 4.17 m/s²
Answer:
The mechanical advantage of the system is 8
Explanation:
the mechanical advantage measures how much the system multiplies the input force to get the output.
In the given:
The input force (effort) is 20 Newton
The output force (load) is 160 Newton
This means that the mechanical advantage is:
mechanical advantage = load / effort = 160 / 20 = 8
Note that the mechanical advantage is unit-less (has no unit) since it is a ratio between two forces.
Hope this helps :)
