Answer:
<em>The force required is 3,104 N</em>
Explanation:
<u>Force</u>
According to the second Newton's law, the net force exerted by an external agent on an object of mass m is:
F = ma
Where a is the acceleration of the object.
On the other hand, the equations of the Kinematics describe the motion of the object by the equation:

Where:
vf is the final speed
vo is the initial speed
a is the acceleration
t is the time
Solving for a:

We are given the initial speed as vo=20.4 m/s, the final speed as vf=0 (at rest), and the time taken to stop the car as t=7.4 s. The acceleration is:


The acceleration is negative because the car is braking (losing speed). Now compute the force exerted on the car of mass m=1,126 kg:

F= 3,104 N
The force required is 3,104 N
Answer:
v(t)= (d/dt)x(t)
Explanation:
The instantaneous velocity of an object is the limit of the average velocity as the elapsed time approaches zero, or the derivative of x with respect to t. Like average velocity, instantaneous velocity is a vector with dimension of length per time. The instantaneous velocity at a specific time point t
0 is the rate of change of the position function, which is the slope of the position function
x
(
t
)
at t
0
.
Explanation:
Relation between potential energy and charge is as follows.
U = qV
or, 
= 
=
J
or, = 
Therefore, we can conclude that change in the electrical potential energy
is
.
Answer:
B : is independent of the natural frequency of the oscillator
Explanation:
You can apply any force you like to a natural oscillator. It is independent of the natural frequency of the oscillator.
The result you get will depend on how the frequency of the applied force and the natural frequency relate to each other. It will also depend on the robustness of the oscillator with respect to the applied force.
Clearly, if the force is small enough, it will have no effect on the oscillator. If it is large enough, it will overpower any motion the oscillator may attempt. For forces in the intermediate range, there will be some mix of natural oscillation and forced behavior. One may modulate the other, for example.
Water expands when it freezes (that's why you should never put closed, fully filled water bottles in the freezer !)