Answer:Fg = mg however newtons second law states that the net force acting on an object is equal to it's mass times it's acceleration so what allows us to say that Fg = mg because certainly not for every single situation the net force is going to equal to the force of gravity please explain... what allows us to say Fg = mg
Source https://www.physicsforums.com/threads/fg-mg-questioned.336776/
Explanation:
Answer:
t = 1.02 s
Explanation:
The computation of the time required is shown below:
The package speed for belt is
= 3 - 1
= 2 m/s
Moreover, the decelerative force would be acted on the block i.e u.m.g
So, the decelerative produced
= 0.2 × 9.81
= 1.962 m/s^2
And, final velocity = 0
v = u - at
here
V = 0 = final velocity
u = 2 m/s
so,
0 = 2 - 1.962 × t
t = 1.02 s
Answer:
Explanation:
If we assume there is a sharp boundary between the two masses of air, there will be a refraction. The refractive index of each medium will depend on the relative speeds of light.
n = c / v
If light travels faster in warmer air, it will have a lower refractive index
nh < nc
Snell's law of refraction relates angles of incidence and refracted with the indexes of refraction:
n1 * sin(θ1) = n2 * sin(θ2)
sin(θ2) = sin(θ1) * n1/n2
If blue light from the sky passing through the hot air will cross to the cold air, then
n1 = nh
n2 = nc
Then:
n1 < n2
So:
n1/n2 < 1
The refracted light will come into the cold air at angle θ2 wich will be smaller than θ1, so the light is bent upwards, creating the appearance of water in the distance, which is actually a mirror image of the sky.
The correct answer is D., density. Hope this helps!
Answer:
a) I = 13.38 kg m / s, b) F = 1,373 10³ N
Explanation:
The impulse is given by the relation
I = ∫ F dt = Δp
I = p_f -p₀
I = m (v_f - v₀)
take the ball's exit direction as positive, whereby the ball velocities
v₀ = -90mph, the final velocity v_f = + 54 m / s
Let's reduce the units to
I = 0.142 [54- (-40.23) ]
the SI system
v₀ = - 90 mph (1609.34 m / 1 mile) (1h / 3600 s = -40.23 m / s
m = 142 g (1kg / 1000) = 0.142 kg
we calculate
I = 0.142 [54- (-40) ]
I = 13.38 kg m / s
b) let's use the definition of momentum
I = ∫ F .dt
I = F ∫ dt
F = I / t
F = 13.38 / 0.008
F = 1,373 10³ N
