Answers:
a) 222.22 m/s
b) 800.00 km/h
Explanation:
The speed of a wave is given by the following equation:
Where:
is the speed
is the frequency, which has an inverse relation with the period 
is the wavelength
Solving with the given units:
This is the speed of the wave in km/h
Transforming this speed to m/s:

This is the speed of the wave in m/s
Imagine a car crash. A car coming at a high speed has a head on collision with a car at rest. When the car makes impact, it will move the other car with it at a slower speed then it was travelling at. In this case, the velocity decreased since the car slowed down, but the mass increased since there are now two cars moving. Momentum was conserved because the change in mass accounts for the loss of velocity.
Answer:you riding your bike at 12m/s
Explanation: this is because momentum P = mass x velocity. With a bigger mass and a velocity of about 12m/s, you really have a great momentum.
Answer:
0.247 μC
Explanation:
As both sphere will be at the same level at wquilibrium, the direction of the electric force will be on the x axis. As you can see in the picture below, the x component of the tension of the string of any of the spheres should be equal to the electric force of repulsion. And its y component will be equal to the weight of one sphere. We can use trigonometry to find the components of the tensions:



The electric force is given by the expression:

In equilibrium, the distance between the spheres will be equal to 2 times the length of the string times sin(50):

And k is the coulomb constan equal to 9 *10^9 N*m^2/C^2. q1 y q2 is the charge of each particle, in this case, they are equal.


O 0.247 μC