Answer:
Power required, P = 175 watts
Explanation:
It is given that,
Weight of a student, F = mg = 200 N
The student climbs a flight of stairs of height, h = 7 m
Time taken, t = 8 s
We have to find the power required to perform this task. Work done per unit time is called the power required. Mathematically, it is given by :
W = work done
t = time taken
P = 175 watts
Hence, the power required to complete this task is 175 watts.
That only the best traits would go through. The weaker trait in the animals would eventually die off.
Answer:
12.5 m.
Explanation:
Speed: This can be defined as the rate of change of distance. The S.I unit of speed is m/s. Mathematically it can be expressed as,
Speed = distance/time
S = d/t......................... Equation 1
d = S×t ...................... Equation 2.
Where S = speed of the car, d = distance, t = time taken to shut the eye during sneezing
Given: S = 90 km/h, t = 0.50 s.
Conversion: 90 km/h ⇒ m/s = 90(1000/3600) = 25 m/s.
S = 25 m/s.
Substitute into equation 2.
d = 25×0.50
d = 12.5 m.
Hence the car will move 12.5 m during that time
Answer: (A) The number of waves that pass a point in a certain amount of time.
Explanation:
Electromagnetic waves are categorized according to their frequency f or, equivalently, according to their wavelength λ = c/f. Visible light has a wavelength range from ~400 nm to ~700 nm.
Frequency: Is the number of waves that pass a certain point in a specified amount of time.
Trough: The low point of the wave cycle.
Wavelength: The distance between two successive peaks.
Electromagnetic wave: One of the waves that are propagated by simultaneous periodic variations of electric and magnetic field intensity.
