Answer:
a)
Explanation:
- A block sliding down an inclined plane, is subject to two external forces along the slide.
- One is the component of gravity (the weight) parallel to the incline.
- If the inclined plane makes an angle θ with the horizontal, this component (projection of the downward gravity along the incline, can be written as follows:
(taking as positive the direction of the movement of the block)
- The other force, is the friction force, that adopts any value needed to meet the Newton's 2nd Law.
- When θ is so large, than the block moves downward along the incline, the friction force can be expressed as follows:
- The normal force, adopts the value needed to prevent any vertical movement through the surface of the incline:
- In equilibrium, both forces, as defined in (1), (2) and (3) must be equal in magnitude, as follows:
- As the block is moving, if the net force is 0, according to Newton's 2nd Law, the block must be moving at constant speed.
- In this condition, the friction coefficient is the kinetic one (μk), which can be calculated as follows:
The radius of the garden hose is
, so its cross-sectional area is
The amount of water (in
) that comes out from the hose in one second is given by the product between the speed of the water and the cross-sectional area of the hose:
The time needed to fill the pool is equal to the volume of the pool divided by the amount of water that comes out every second:
Answer:
k = 52.2 N / m
Explanation:
For this exercise we are going to use the conservation of mechanical energy.
Starting point. When it is 30 m high
Em₀ = K + U = ½ m v² + m g h
Final point. Right when you hit the water
= K_{e} = ½ k x²
in this case the distance the bungee is stretched is 30 m
x = h
as they indicate that there are no losses, energy is conserved
Em₀ = Em_{f}
½ m v² + m g h = ½ k h²
k =
let's calculate
k =
k = 52.2 N / m
Answer:
Because of immense gravity
Explanation:
The formation of the Solar system was a very dynamic process. A lot of matter was thrown towards the outer solar system which further formed the Gas giants: Jupiter, Saturn, Uranus, and Neptune. The size of these outer planets is huge so is their gravity.
Because of their huge gravity a lot of matter which was scattered in the outer solar system got attracted towards them. This matter is what make the rings of the outer planets. Also, because of immense gravity they captured larger bodies thus making them their Moons.
The speed of sound in a solid would be 6000 metres per second