Answer:
The value of F= - 830 N
Since the force is negative, it implies direction of the force applied was due south.
Explanation:
Given data:
Mass = 1000-kg
Distance, d = 240 m
Initial velocity, v1 = 20.0 m/s
Final velocity, v2 = 0 (since the car came to rest after brake was applied)
v2²= v1² + 2ad (using one of the equation of motion)
0= 20² + (2 x a x 240)
0= 400 + 480 a
a = - 400/480
a = - 0.83 m/s²
Then, imputing the value of a into
F = ma
F = 1000 kg x ( - 0.83 m/s²)
F= - 830 N
The car was driving toward the north, and since the force is negative, it implies direction of the force applied was due south.
The best way to deterime which cloth with absorb heat is to put each cloth outside in the heat with a thermometer under it and see which has the highest tempe.
The way I look at these things is like this:
-- The runner covered 12 meters in 4 seconds.
Average speed = 3 meters per second.
-- Speed at the beginning = zero.
In order to make the average 3, Speed at the end = 6 meters per second.
-- Speed increased from zero to 6 meters per second in 4 seconds.
It must have increased 1.5 meters per second each second.
That's choice-#2.