Answer:
the answer is A.) -1 * 10^3[N]
Explanation:
The solution consists of two steps, the first step is using the following kinematic equation:
![v=v_{i} +a*t\\where:\\v=final velocity [m/s]\\v_{i}=initial velocity [m/s]\\a=acceleration[m/^2]\\t=time[s]\\](https://tex.z-dn.net/?f=v%3Dv_%7Bi%7D%20%2Ba%2At%5C%5Cwhere%3A%5C%5Cv%3Dfinal%20velocity%20%5Bm%2Fs%5D%5C%5Cv_%7Bi%7D%3Dinitial%20velocity%20%5Bm%2Fs%5D%5C%5Ca%3Dacceleration%5Bm%2F%5E2%5D%5C%5Ct%3Dtime%5Bs%5D%5C%5C)
The initial velocity is 10 [m/s], and the final velocity is zero because the car stops in 0.5[s].
Replacing:
![0=10+a*(0.5)\\a=-20[m/s^2]](https://tex.z-dn.net/?f=0%3D10%2Ba%2A%280.5%29%5C%5Ca%3D-20%5Bm%2Fs%5E2%5D)
Now in the second part, we need to use the second law of Newton, this law relates the forces with the acceleration of a body.
In the moment when the car stops suddenly the driver will feel the force of the seatbelt acting in the opposite direction of the movement.
![F=m*a\\F=50[kg]*(-20[m/s^2])\\units\[kg]*[m/s^2]=[N]\\F=-1000[N] or -1*10^{3} [N]](https://tex.z-dn.net/?f=F%3Dm%2Aa%5C%5CF%3D50%5Bkg%5D%2A%28-20%5Bm%2Fs%5E2%5D%29%5C%5Cunits%5C%5Bkg%5D%2A%5Bm%2Fs%5E2%5D%3D%5BN%5D%5C%5CF%3D-1000%5BN%5D%20or%20-1%2A10%5E%7B3%7D%20%5BN%5D)
The minus sign means that the force is acting in the opposite direction of the movement.
Answer:
18.33 Ns
Explanation:
As the pitch back speed has the opposite direction as before, the change in velocity would be
So the change in momentum of the ball would be the product of its velocity change and its mass
This is equals to the impulse acted on the ball by the bat, which is 18.33 Ns
Answer:
The tension is 75.22 Newtons
Explanation:
The velocity of a wave on a rope is:
(1)
With T the tension, L the length of the string and M its mass.
Another more general expression for the velocity of a wave is the product of the wavelength (λ) and the frequency (f) of the wave:
(2)
We can equate expression (1) and (2):
=
Solving for T
(3)
For this expression we already know M, f, and L. And indirectly we already know λ too. On a string fixed at its extremes we have standing waves ant the equation of the wavelength in function the number of the harmonic 
is:
It's is important to note that in our case L the length of the string is different from l the distance between the pin and fret to produce a Concert A, so for the first harmonic:
We can now find T on (3) using all the values we have:
Answer:
Explanation: When the electrons move in another direction, they convert this chemical potential energy to electricity in the circuit, thus discharging the battery. So, the battery is all potential energy.
