Answer:
Both balls have the same speed.
Explanation:
Janelle throws the two balls from the same height, with the same speed. Both balls will have the same potential and kinetic energy. Energy must be conserved. When the balls pass Michael, again they must have the same potential and kinetic energy.
Answer:
<em>To reverse the direction of an electric current, we simply reverse the voltage either automatically with the help of some switching circuitry or manually by changing the voltage source terminals connection. </em>
Explanation:
For electric current to flow, there must be a potential difference, usually referred to as the voltage. The electric current flow is analogous to the flow of water under the action of a pump, through a series of pipe connections. The voltage is similar to the driving action of the pump, and current flows the same way water flows. The resistance due to drag on the pipe wall is equivalent to electric resistance. For current to flow in the reverse direction, the voltage or rather, the potential difference is changed, causing the current to flow in the opposite direction. This can be done by switching the terminals of the voltage source, or by automatic means. The automatic switching can be done with a transistor based circuitry.
Newtons third law of motion applies to football as when the ball is thrown, force is applied to the football thrown forward and also force back to the player. Therefore it states that every action has a reaction. The player does not get a huge force back from throwing the football due to the player having a bigger mass than the football being thrown.
In short, when the football is throw, there is a reaction with the ball and the player accordingly with the force put into the ball.
Answer:
a) x = 8.8 cm * cos (9.52 rad/s * t)
b) x = 8.45 cm
Explanation:
This is a Simple Harmonic Motion, and most Simple Harmonic Motion equations start from the equilibrium point. In this question however, we are starting from the max displacement the equations, and thus, it ought to be different.
From the question, we are given that
A = 8.8 cm = 0.088 m
t = 0.66 s
Now, we need to find the angular speed w, such that
w = 2π/T
w = (2 * 3.142) / 0.66
w = 6.284 / 0.66
w = 9.52 rad/s
The displacement equation of Simple Harmonic Motion is usually given as
x = A*sin(w*t)
But then, the equation starts from the equilibrium point at 0 sec, i.e x = 0 m
When you have to start from the max displacement, then the equation would be
x = A*cos(w*t).
So when t = 0 the cos(0) = 1, and then x = A which is max displacement.
Thus, the equation is
x = 8.8 cm * cos (9.52 rad/s * t)
At t = 1.7 s,
x = 8.8 cos (9.52 * 1.7)
x = 8.8 cos (16.184)
x = -8.45 cm
