Answer: 3 A
Explanation:
According to<u> Ohm's law</u>:
Where:
is the voltage
is the resistance of the resistor
is the electric current (the value we want to find)
Isolating :
Finally:
100 Joules have been used to roll the object up the ramp, but only 90 Joules were actually needed to lift the object, this means that 10 Joules have been wasted in the form of heat due to the friction between the object and the ramp, and this corresponds to
so, 10 % of the energy.
Answer: The answer is in the figure attached.
Explanation:
The Work done by a Force refers to the release of potential energy from a body that is moved by the application of that force to overcome a resistance along a path.
It should be noted that it is a scalar magnitude, and its unit in the <u>International System of Units</u> is the Joule (J). Therefore, 1 Joule is the work done by a force of 1 Newton when moving an object, in the direction of the force, along 1 meter:
However, in the British Engineering and Gravitational Systems its unit is Foot-pound (ft-lb). Where
Now, when the applied force is constant and the direction of the force and the direction of the movement (traveled distance) are parallel, the equation to calculate it is:
So, taking into account the explanation above, the attached table shows the Work done for each situation.
As the hard disk makes 360 revolutions per second, so one full rotation requires 1/360 sec = 0.002778 sec = 2.778 ms.
On average, however, we expect to require half a rotation. Therefore, we need 1.389 ms. The second part of the movement depends on the seek time which is 10 ms. Therefore, the total time is 1.389+10=11.389 ms on average.
20m/s, honestly I have know idea what the asnwer is but if i had to guess, this would be my answer.