Answer:
a.14 s
b.70 s
Explanation:
a.Let the sidewalk moving in positive x- direction.
Speed of sidewalk relative to ground=
Speed of women relative to sidewalk=v=1.5m/s
The speed of women relative to the ground

Distance=35 m
Time=
Using the formula
Time taken by women to reach the opposite end if she walks in the same direction the sidewalk is moving=
b.If she gets on at the end opposite the end in part (a)
Then, we take displacement negative.
Speed of sidewalk relative to ground=
Speed of women relative to sidewalk=v=-1.5 m/s
The speed of women relative to the ground=
Time=
Hence, the women takes 70 s to reach the opposite end if she walks in the opposite direction the sidewalk is moving.
Energy of a wave:
E = nhc/λ
3000 = (n x 6.63 x 10⁻³⁴ x 3 x 10⁸)/(510 x 10⁻⁹)
n = 7.69 x 10 ²¹ photons per second per meter²
2.70 cm² = 2.70/10,000 m²
= 2.7 x 10⁻⁴
Photons per second = 7.69 x 10 ²¹ x 2.7 x 10⁻⁴
= 2.08 x 10¹⁸ photons per second
Answer:
D
Explanation:
If you list and compare, the elephants hearing range is the closest to a humans.
Humans: 20-20,000
Elephant: 16-12,000
While the others are either too much more or less than a humans.
Bat: 2,000-110,000
Dolphin: 90-105,000
Chicken: 125-2,000
Answer:
Explanation:
If the force of 2000 N is directed towards the right and the friction is directed towards the left, the 2000 N force is positive and the other is negative. To find the resultant force:
2000 - 500 = 1500 N to the right
Answer:
The answer is a 1 kilo gold bar has 32.15 ounces of gold or 1000 grams.
Explanation: