Answer:
It is explained in the explanation section
Explanation:
When the lift starts going downwards, it will start accelerating downwards. After a while, it will start moving with a constant velocity.
Constant velocity means that acceleration is zero and so the man will not feel any weight loss.
Now, Once the lift achieves constant velocity the acceleration is zero hence he will not experience any weight loss.
However, when the lift is in uniform motion, the lift and the man will fall down with an acceleration(a) that is less than that due to gravity(g) . Thus, the man will feel an apparent weight F which is not equal to zero.
Answer:
6m/s
Explanation:
Given parameters:
Initial velocity = 0m/s
Acceleration = 2m/s²
Distance = 9m
Unknown:
Final velocity = ?
Solution:
To solve this problem, we use the expression below:
v² = u² + 2as
v is the final velocity
u is the initial velocity
a is the acceleration
s is the distance
v² = 0² + (2 x 2 x 9) = 36
v = 6m/s
The letter D represents the wavelength
Answer
Any force greater 490N
Explanation
The force required just to make an object slide over a rough horizontal surface is any force greater that the static friction which given by;

Given;

Hence;
F = 0.5 x 100 x 9.8
F = 490N.
We will only need the coefficient of kinetic friction if we were asked to find the force required to keep the object moving uniformly. Usually, the force needed to keep an object moving uniformly over a rough surface is lesser that which is needed to start its motion.
In this problem, we were only asked to find the minimum force required to make the object move which we have done.
Ike is at the beach watching the waves in the ocean. Ike notices that some of the waves are short. Other waves are very tall and come up high above the water. Two waves that are different heights because They have different amplitudes.
Answer: Option (D) is correct
Explanation:
The different heights of the waves are due to their different amplitudes. The Amplitude of a particular wave depends upon the amount of energy being carried by waves. It the waves carry more energy than their amplitude will be higher.
But if energy carried by a wave is less than the wave will have a low amplitude. The Amplitude shows the distance covered from the rest position to peak position.