Answer:
B. Electrons are transferred from the fur to the plastic rod.
Explanation:
Triboelectricity or friction charging refers to the ability of materials to gain or lose electrons as a result of rubbing them against something. This phenomenon has been observed in the case of rubbing plastic rod against fur, or glass rod against silk.
In the context of rubbing plastic rod against fur, what happens is that the fur which has an excess of charges loses electrons to the plastic rod. This makes the plastic rod to become positively charged, and the fur, negatively charged.
Answer:
Before:


After:




Explanation:
<u>Conservation of Momentum</u>
Two objects of masses m1 and m2 moving at speeds v1o and v2o respectively have a total momentum of

After the collision, they have speeds of v1f and v2f and the total momentum is

Impulse J is defined as

Where F is the average impact force and t is the time it lasted
Also, the impulse is equal to the change of momentum

As the total momentum is conserved:


We can compute the speed of the second object by solving the above equation for v2f

The given data is


a) The impulse will be computed at the very end of the answer
b) Before the collision


c) After collision

Compute the car's speed:


And the car's momentum is

The Impulse J of the system is zero because the total momentum is conserved, i.e. \Delta p=0.
We can compute the impulse for each object

The force can be computed as

The force on the car has the same magnitude and opposite sign
Answer:
Reduce the friction at the surface
Explanation:
If you can reduce the friction between the load and the plane less effort will be required as you are not having to apply effort to overcome friction.
Answer: y(t)= 1/π^2 sin(6*π^2*t)
Explanation: In order to solve this problem we have to consider the general expression for a harmonic movement given by:
y(t)= A*sin (ω*t +φo) where ω is the angular frequency. A is the amplitude.
The data are: ν= 3π; y(t=0)=0 and y'(0)=6.
Firstly we know that 2πν=ω then ω=6*π^2
Then, we have y(0)=0=A*sin (6*π^2*0+φo)= A sin (φo)=0 then φo=0
Besides y'(t)=6*π^2*A*cos (6*π^2*t)
y'(0)=6=6*π^2*A*cos (6*π^2*0)
6=6*π^2*A then A= 1/π^2
Finally the equation is:
y(t)= 1/π^2 sin(6*π^2*t)