Answer:
The focal length of eyepiece is 3.68 cm.
Explanation:
Given that,
Distance = 19 cm
Focal length = 5.5 mm
Magnification = 200
Object distance = -25 cm
We need to calculate the focal length
Using formula of magnification

Put the value into the formula


Hence, The focal length of eyepiece is 3.68 cm.
Answer:
The final pressure of the gas is 9.94 atm.
Explanation:
Given that,
Weight of argon = 0.16 mol
Initial volume = 70 cm³
Angle = 30°C
Final volume = 400 cm³
We need to calculate the initial pressure of gas
Using equation of ideal gas


Where, P = pressure
R = gas constant
T = temperature
Put the value in the equation



We need to calculate the final temperature
Using relation pressure and volume



Hence, The final pressure of the gas is 9.94 atm.
Answer:
Statement 2 is wrong
Explanation:
To check the statements in this exercise, let's describe the main properties of electromagnetic waves. Let's describe the characteristics
* they are transverse waves
* formed by the oscillations of the electric and magnetic fields
* the speed of the wave is the speed of light
with these concepts let's review the final statements
1) True. Formed by the oscillation of the two fields
2) False. They are transverse waves
3) True. Can travel by vacuum as they are supported by oscillations of the electric and magnetic fields
4) True. They all have the same speed of light
Statement 2 is wrong
Answer:
$4.2
Explanation:
Given data
Power= 700W
time= 10 hours
Cost per kilowatt hours is cents $0.20
Let us find the number of hours in a month
=24*30
=720 hours
Energ= power*time
Energy= 700/1000*30
Energy= 7*3
Enery= 21 kwh
1 kwh= 0.2
21kwh= x
cross multiply
x=21*0.2
x= $4.2
Answer:
Speed of the ball relative to the boys: 25 km/h
Speed of the ball relative to a stationary observer: 35 km/h
Explanation:
The RV is travelling at a velocity of

Here we have taken the direction of motion of the RV as positive direction.
The boy sitting near the driver throws the ball back with speed of 25 km/h, so the velocity of the ball in the reference frame of the RV is

with negative sign since it is travelling in the opposite direction relative to the RV. Therefore, this is the velocity measured by every observer in the reference frame of the RV: so the speed measured by the boys is
v = 25 km/h
Instead, a stationary observer outside the RV measures a velocity of the ball given by the algebraic sum of the two velocities:
v = +60 km/h + (-25 km/h) = +35 km/h
So, he/she measures a speed of 35 km/h.