Answer:
a) false
b) True
c) True
d) False
e) False
Explanation:
a) False
For a diverging lens, the focal length is negative while it is positive for a converging lens
b) True
Image distances for virtual images are always negative and it also forms on the the same side of the lens as the object and is enlarged
c) True
d) False
For a diverging lens, the focal length is negative while it is positive for a converging lens
e) False
Image distances for virtual images are always negative and it also forms on the the same side of the lens as the object and is enlarged
Answer: ma is the formula of Newton's Second Law of Motion. Newton's Second Law of Motion is defined as Force is equal to the rate of change of momentum. For a constant mass, force equals mass times acceleration.
Explanation: Newton's second law of motion is F = ma, or force is equal to mass times acceleration.
Explanation:
When a constant force acts upon an object the acceleration of the object varies inversely with its mass.

or

If m₁ = 21 kg, a₁ = 3 m/s², m₂ = 9 kg
We need to find a₂
So,

So, if mass is 9 kg, its acceleration is 7 m/s².
Answer:
0.2 m
Explanation:
PHASE 1
First, we calculate the distance the tongue moved in the first 20 ms (0.02 secs). We use one of Newton's equations of linear motion:

where u = initial velocity = 0 m/s
a = acceleration = 
t = time = 0.02 s
Therefore:

PHASE 2
Then, for the next 30 ms (0.03 secs), we use the formula:

This speed is the same as the final velocity of the tongue after the first 20 ms.
This can be obtained by using the formula:

Therefore:
distance = 5 * 0.03 = 0.15 m
Therefore, the total distance moved by the tongue in the 50 ms interval is:
0.05 + 0.15 = 0.2 m
Answer:
Mechanical Waves
Explanation:Sound waves in air are longitudinal waves because particles of the medium through which the sound is transported vibrate parallel to the direction that the sound wave moves. A vibrating string can create longitudinal waves.