Answer:
70 m.
Explanation:
Given,
Frequency, f = 20 HZ
speed of sound, v = 1400 m/s
wavelength of the waves = ?
we know,
v = f λ



Hence, the wavelength of the wave is equal to 70 m.
It’s newton’s 2nd law of motion
Answer:
2.42hours
Explanation:
To calculate the time taken to boil the cup of water, we will use the formula
Q = It where
Q is the total energy required to boil the water = 100KJ = 100,000Joules
I is the current = 11.5A
t is the time taken to boil the water
t = Q/I
t = 100,000/11.5
t = 8695.65seconds
t = 2.42hours
A) 500 calories
B)5000 joules
C) 5 kilocalories
Answer is C