Answer:
Explanation:
The tidal current flows to the east at 2.0 m/s and the speed of the kayaker is 3.0 m/s.
Let Vector
is the tidal current velocity as shown in the diagram.
In order to travel straight across the harbor, the vector addition of both the velocities (i.e the resultant velocity,
must be in the north direction.
Let
is the speed of the kayaker having angle \theta measured north of east as shown in the figure.
For the resultant velocity in the north direction, the tail of the vector
and head of the vector
must lie on the north-south line.
Now, for this condition, from the triangle OAB




Hence, the kayaker must paddle in the direction of
in the north of east direction.
Answer:
12 cm and 0.4
Explanation:
f = - 20 cm, u = - 30 cm
Let v be the position of image and m be the magnification.
Use lens equation
1 / f = 1 / v - 1 / u
- 1 / 20 = 1 / v + 1 / 30
1 / v = - 5 / 60
v = - 12 cm
m = v / u = - 12 / (-30) = 0.4
Answer:
Explanation:
Theoretical efficiency = T₁ - T₂ / T₁ where T₁ and T₂ is absolute temperature of hot and cold end of the heat engine.
= 600 / (273 + 700 )
= 600 / 973
= .6166
operating efficiency = 40% of .6166
= .4 x .6166
= .2466 = 24.66 %
efficiency = work output / heat input
= 5000 / heat input = .2466
heat input = 5000 / .2466
= 20275.75 J .
HEAT EXTRACED = 20275.75 J.
Answer:
A protractor to measure the angle of the inclined plane with the horizontal
Explanation:
The student needs to lift the free end of the adjustable inclined plane until the object barely starts sliding, and measure the angle at which such happens. At that point, the force of friction equals the component of the weight in the direction of the incline. That is:

and 
Then

and therefore, the coefficient of static friction is fully determined just by calculating the tangent of the angle that the incline forms with the horizontal.
Then the only extra instrument needed is a protractor to measure the angle.
Answer is B. Atoms must be bonded together to create molecules.