Answer:
(a)
(b) h is the same
Explanation:
According to the law of conservation of energy:

The skier starts from rest, so
and we choose the zero point of potential energy in the end of the ramp, so
. We calculate the final speed, that is, the speed when the skier leaves the ramp:

Finally, we calculate the maximum height h above the end of the ramp:

The initial vertical speed is given by:

and the final speed is zero, solving for h:

(b) We can observe that the height reached does not depend on the mass of the skier
Answer:
E. Some charges in the region are positive, and some are negative.
Explanation:
Electric potential is given as;

where;
W is the work done in moving a charge between two points which have a difference in potential
Q is quantity of charge in the given region
If the electric potential at a given point in the region is zero, then sum of the charges in the given region must be equal to zero. For the charges to sum to zero, some will be positive while some will be negative,.
Therefore, the correct statement in the given options is "E"
E. Some charges in the region are positive, and some are negative.
Answer:
q = 13 C
Explanation:
Given that,
Electric current, I = 20 A
The starter motor runs for 0.65 s before the car engine starts up.
We need to find how much of electric charge passes through the starter motor. Let it is q.
Electric current = electric charge/time

So, 13 C of electric charge passes through the starter motor.
Answer
given,
copper rod length = 50 cm
density of the copper = 8.92 g/cm³
iron rod length = 50 cm
density of iron = 7.86 g/cm³
mass of iron = density × volume
m_i = 7.86 × A × l/2
m_c = 8.96 × A × l/2
taking the intersection of copper and iron rod be starting point cooper side is taken as positive side and iron side length is taken to be -ve side.
center of mass
= 
= 
= 
= 
= 0.015793 m
= 1.579 m (+ve)
center of mass shift to cooper because cooper is heavy.
When you graph simple harmonic motion in an acceleration versus displacement graph, the graph at any point would be linear. The graph would also pass through the origin giving proportionality of acceleration to negative displacement. Definition of proportionality neglects the negative value of the displacement so therefore acceleration is proportional to displacement. The acceleration of the motion is always directed towards equilibrium and so at maximum displacement, there would be greatest negative acceleration and vise versa.At the origin, the displacement would be zero and acceleration would also be zero