Newton's third law of motion states that for any action, there is equal and opposite force. For a person standing on a floor, the action force is the weight and thus the floor must exert an opposite and equal reaction force equivalent in magnitude to the weight of the person.
In this regard, statement 3. is correct.
Answer: $85.80
Explanation: 100kg is equalvilent to 220 lbs, then you multiply 220 by .39 and then you have your answer :)
Answer:
Can enter or leave the system matter and energy. (The correct option is D)
Explanation:
Open system is defined as the system where exchange of matter, and energy occurs with its surrounding, presenting breaking down, and build up of its materials, and import, export of components.
Open system transfer the material into, and out of the system boundary, it contains an external interaction. A good example of open system is living things they actively connect with its environment, in results it shows changes in both the environment, and the living things.
So, the correct option is D.
Answer:
t = 376.99 s
Explanation:
We must solve this problem with the equations and kinematics, let's start by looking for the speed of the vehicle,
v = d / t
v = 7/40
v = 0.175 m / s
Since the speed e remains constant, we must find the length of the circle is
L = 2π r
L = 2π 21
L = 131.95 m
In the problem it does not specify clearly, but in general the curves of the road correspond to half a circle, so the length of the road is
L ’= L / 2
L ’= 131.95 / 2 = 65.97 m
as the speed is constant
t = L ’/ v
t = 65.97 / 0.175
t = 376.99 s