Answer:
Explanation:
Given:
- Distance from the shore,
- distance of house from the shore,
- speed of rowing,
- speed of walking,
<em>For the least amount of time to reach the house one must row at the nearest point on the shore and then walk from there.</em>
<u>Now the time taken to reach the shore:</u>
<u>Time taken in walking to house from the shore:</u>
<u>Therefore total time taken:</u>
The initial voltage at the primary= 750 V
Explanation:
for a transformer
Es/ Ep= Ns/ Np
Es= secondary voltage= 240 V
Ep= primary voltage
Ns= number of turns in the secondary=8
Np= Number of turns in the primary=25
so 240/Ep=8/25
Ep=750 V
If the two forces act in the same direction, their resultant is 13N .
If they act in opposite directions, their resultant is 3N .
These are the limits. The resultant is always between 3N and 13N.
So (B), (C), and (D) (3N, 10N, and 13N are possible.)
<em>(A)</em> 2N is not possible.
The component of the crate's weight that is parallel to the ramp is the only force that acts in the direction of the crate's displacement. This component has a magnitude of
<em>F</em> = <em>mg</em> sin(20.0°) = (15.0 kg) (9.81 m/s^2) sin(20.0°) ≈ 50.3 N
Then the work done by this force on the crate as it slides down the ramp is
<em>W</em> = <em>F d</em> = (50.3 N) (2.0 m) ≈ 101 J
The work-energy theorem says that the total work done on the crate is equal to the change in its kinetic energy. Since it starts at rest, its initial kinetic energy is 0, so
<em>W</em> = <em>K</em> = 1/2 <em>mv</em> ^2
Solve for <em>v</em> :
<em>v</em> = √(2<em>W</em>/<em>m</em>) = √(2 (101 J) / (2.0 m)) ≈ 10.0 m/s
