Answer:
159 N
Explanation:
The force of friction is a resistive force that acts against an object in motion (or on the verge of moving).
There are two types of force of friction:
- Force of static friction: it occurs when the object is still at rest
- Force of kinetic friction: it occurs when the object is sliding on a surface and it is in motion
In this problem, we are in the 2nd situation, so we want to calculate the force of kinetic friction.
This force is given by:

where
is the coefficient of kinetic friction
N is the normal force exerted on the object
For the sled and the girl in this problem,
is the coefficient of kinetic friction
N = 636 N is the normal force
So the force of friction is

Answer:
E = 1.04*10⁻¹ N/C
Explanation:
Assuming no other forces acting on the proton than the electric field, as this is uniform, we can calculate the acceleration of the proton, with the following kinematic equation:

As the proton is coming at rest after travelling 0.200 m to the right, vf = 0, and x = 0.200 m.
Replacing this values in the equation above, we can solve for a, as follows:

According to Newton´s 2nd Law, and applying the definition of an electric field, we can say the following:
F = mp*a = q*E
For a proton, we have the following values:
mp = 1.67*10⁻²⁷ kg
q = e = 1.6*10⁻¹⁹ C
So, we can solve for E (in magnitude) , as follows:

⇒ E = 1.04*10⁻¹ N/C
Radioisotopes is a atom with unstable nuclei. They also decay to change different from the electrons over time.
Hope it helped you.
-Charlie
Answer:
8ft/s
Explanation:
For computing the average velocity of the cork first we have to determine the frequency which is shown below:


= 4 Hz
Now the average velocity of the cork is

= 8ft/s
We simply applied the above formulas to determine the frequency and the velocity of the cork during this motion and the same is to be considered