Answer:
Explanation:
<u>Net Force
</u>
The second Newton's law explains how to understand the dynamics of a system where several forces are acting. The forces are vectorial magnitudes which means the x and y coordinates must be treated separately. For each component, the net force must equal the mass by the acceleration, i.e.
The box with mass m=20 kg is pulled by a rope with a angle above the horizontal. It means that force (called T) has two components:
We'll assume the positive directions are to the right and upwards and that the box is being pulled to the right. There are two forces in the x-axis: The x-component of T (to the right) and the friction force (to the left). So the equilibrium equation for x is
There are three forces acting in the y-axis: The component of T (upwards), the weight (downwards), and the Normal (upwards). Since there is no movement in the y-axis, the net force is zero and:
Rearranging:
Solving for N in the y-axis:
The friction force is given by
Replacing in the equation for the x-axis, we have
Replacing the formula for N in the equation for the x-axis
Operating and rearranging
Solving for T:
Plugging in the given values:
Answer:
1st law--Newton's first law states that every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force. This is normally taken as the definition of inertia. The key point here is that if there is no net forceacting on an object (if all the external forces cancel each other out) then the object will maintain a constant velocity. If that velocity is zero, then the object remains at rest. If an external force is applied, the velocity will change because of the force.
2nd— The second law explains how the velocity of an object changes when it is subjected to an external force. The law defines a force to be equal to change in momentum(mass times velocity) per change in time. Newton also developed the calculus of mathematics, and the "changes" expressed in the second law are most accurately defined in differential forms. (Calculus can also be used to determine the velocity and location variations experienced by an object subjected to an external force.) For an object with a constant mass m, the second law states that the force F is the product of an object's mass and its acceleration a:
F = m * a
For an external applied force, the change in velocity depends on the mass of the object. A force will cause a change in velocity; and likewise, a change in velocity will generate a force. The equation works both ways.
3rd law-- The third law states that for every action (force) in nature there is an equal and opposite reaction. In other words, if object A exerts a force on object B, then object B also exerts an equal force on object A. Notice that the forces are exerted on different objects. The third law can be used to explain the generation of lift by a wing and the production of thrust by a jet engine.
Answer:
The contraction in the rod is 71 mm.
Explanation:
Given that,
original length L'= 2.99 m
Speed
We need to calculate the length
Using expression for length contraction
Where,
Where, v = speed of observer
c = speed of the light
Put the value into the formula
The expression for the contraction in the rod
Hence, The contraction in the rod is 71 mm.
Answer:
In most cases, the sources of information for both levels are same as follows:
Verbal or personal contacts : This information is transferred through verbal method. ...
Different media: Media is one of the best sources of information in these days.
Explanation: