The forces acting on the book (Fn and Fg) are equal. Therefore, the netforce is zero and it is an unbalanced force.
Answer:
wave speed= constant
frequency = increase
wavelength = decrease
Explanation:
Solution:
- The three basic parameters of a wave are speed, frequency and wavelength. These three parameters are related to each other by an expression:
v = f * λ
Where,
- v is the speed of the wave in m/s.
- f frequency of the wave in Hz.
- λ wavelength of the wave in m
- We are asked how would each of these parameter change if we move the hand up and down faster. The hand moves from a crest to trough faster than before and back again. We can see that the time between a cycle has decreased; hence, frequency f increases. Consequently, we can see that wave speed v remains constant - the medium of transfer of wave energy - remains same. Then from our relation above if we hold speed constant and increase f then the wavelength λ would have to decrease.
The sloping surface of the inclined plane<span> supports part of the weight of the object as it moves up the slope. As a result, it takes less </span>force<span> to move the object uphill. The </span>trade<span>-off </span>is<span> that the object must be moved over a greater </span>distance<span> than if it were moved straight up to the higher elevation.</span>
Answer:
13.02 m/s the velocity and 86.92 degrees the direction relative to ground
Explanation:
We need to add velocities in vector addition to find the resultant velocity "
" of the balloon (the 13 m/s and the 0.7 m/s).
The velocities are at 90 degrees from each other (one pointing up and the other to the East). Notice from the attached image that the resultant velocity vector (picture in red) is actually the hypotenuse of a right angle triangle.
So we use Pythagoras to find the length (magnitude) of the resultant velocity vector:
we can round the answer to 13.02 m/s
Now we need to find the angle that this new vector makes with the ground by using the definition of tangent of an angle that relates the two quantities that we just added:
So we round it to 86.92 degrees
Answer:
The difference between the cost of operating LED and incandescent bulb is $5.1
Explanation:
We are given the cost of electricity that is 12.75 cents per kWh. We want to find out the difference in the operating cost of an incandescent and LED bulb for a time period of 2,000 hours.
Since we are not given the rating of the incandescent bulb and LED bulb, we will assume their ratings.
For a light intensity of 250 Lumens;
The average rating of an LED bulb is approximately 5 Watts.
The average rating of an incandescent bulb is approximately 25 Watts.
Now lets find out the kWh of each bulb.
Energy = Power×Time
For LED bulb:
E = 5×2,000 = 10,000 Wh
Divide by 1000 to convert into kWh
E = 10,000/1000 = 10 kWh
Cost = 12.75×10 = 127.5 cents
Cost = $1.27
For Incandescent bulb:
E = 25×2,000 = 50,000 Wh
Divide by 1000 to convert into kWh
E = 50,000/1000 = 50 kWh
Cost = 12.75×50 = 637.5 cents
Cost = $6.37
Difference in Cost:
Difference = $6.37 - $1.27 = $5.1
Therefore, the difference between the cost of operating LED and incandescent bulb is $5.1.
