Answer:
69.74 N
Explanation:
We are given that
Weight of sled=49 N
Coefficient of kinetic friction
Weight of person=585 N
Total weight==mg=49+585=634 N
We know that
Force needed to pull the sled across the snow at constant speed,F=Kinetic friction

Where N= Normal=mg

Hence, the force is needed to pull the sled across the snow at constant speed=69.74 N
Answer:
T/√8
Explanation:
From Kepler's law, T² ∝ R³ where T = period of planet and R = radius of planet.
For planet A, period = T and radius = 2R.
For planet B, period = T' and radius = R.
So, T²/R³ = k
So, T²/(2R)³ = T'²/R³
T'² = T²R³/(2R)³
T'² = T²/8
T' = T/√8
So, the number of hours it takes Planet B to complete one revolution around the star is T/√8
Answer:
A. The wavelength doubles but the wave speed is unchanged
Explanation:
The relationship between the period and wavelength is direct. Doubling the period of the oscillator will correspondingly double the wavelength but the wave speed is unaffected
decreased 5 times
Explanation: if the force increases 5 times between them would decrease 5 times