To determine the velocity of an object, you would need to know it's magnitude and direction, because velocity is the speed is a certain direction. <span />
Answer:
i = 1.2 [amp].
Explanation:
In order to find the current in the circuit, we must perform a sum of voltages equal to zero, around the mesh.
∑V = 0
Let's take the direction of the current as shown in the drawing Clockwise.
Note: The negative sign means that the current moves in a counterclockwise direction.
i don't know the anss , sorry.
The potential energy of the ball before it falls is (mass) (gravity) (height) =
(0.5 kg) (9.8 m/s²) (4 m) = 19.6 joules
The kinetic energy of the ball when it hits the ground is (1/2) (mass) (speed)² =
(1/2) (0.5 kg) (5 m/s)² = (0.25 kg) (25 m²/s²) = 6.25 joules
a). The <em>energy lost</em> to air resistance during the fall is (19.6J - 6.25J) = <em>13.35 Joules. </em><em>Energy is never destroyed, so these missing joules had to go somewhere. This is the </em><em>work done on the ball by air resistance</em><em> during the fall of the ball.</em>
b). Air resistance worked on the ball all during the fall of 4 meters.
Work = (force) x (distance)
13.35 Joules = (force) x (4 meters)
Divide each side by (4 meters) :
Average force = (13.35 Joules / 4 meters)
<em>Average force = 3.3375 Newtons</em>
Answer:
Explanation:
ME initial = ME final
PE initial + KE initial = PE final + KE final
There's no kinetic energy the moment Jorge is at the top of the ramp therefore KE initial = 0
PE initial = PE final + KE final
Assuming the bottom of the ramp is h = 0 we can then say PE final = 0
PE initial = KE final
Write the equations out.
mgh = (.5)mv^2
They tell us potential energy is 6000J therefore that portion of the equation is already "solved"
6000 = (.5)mv^2
Plugin the values
6000 = (.5) 70 v^2
Solve for v
6000 = 35v^2
171.43 = v^2
13.1 = v at the bottom of the slope
Solving for KE we get
(.5) m v^2
Plugin the value from the previous problem and solvee!