Answer:
Explanation:
You can ignore how high the window actually is, unless the calculator falls further. You just want to use the formula v_f = v_i + at Let em know if that doesn't help and I can work you through it.
To check the distance use y = v_i*t + .5at^2. Would just plug in 0*1.8 + .5(-9.8)1.8^2 = -15.876, so it doesn't fall more than 20.7 m so indeed, you don't have to worry about that.
Again, let me know if you need further help.
Answer:
Explanation:
A )
v² = u² + 2 a s
u = 0
s = 2.5
a = 9.8
v² = 2 x 9.8 x 2.5 = 49
v = 7 m /s
B )
time required to fall by first 2.5 m , t₁
s = 1/2 a t₁²
2.5 = .5 x 9.8 t₁²
t₁ = .714 s
time required to fall by 10 m
s = 1/2 a t₂²
10 = .5 x 9.8 t₂²
t₂ = 1.43 s
time required to fall by last 7.5 m
= t₂ - t₁
= 1.43 - .714
= .72 s
C )
time taken by second = .72 s
For second let initial velocity required be u
s = ut + 1/2 g t²
10 = u x .72 + .5 x 9.8 x .72²
10 = u x .72 + 2.54
u = 10.36 m /s
We have to speed up the watch so we need to decrease time period of pendulum. So we hv to reduce the length.
A line that's 'normal' to the surface is perpendicular to the surface.
The angle of incidence is the angle between the normal and the light ray ARRIVING at the surface.
The angle of reflection is the angle between the normal and the light ray LEAVING the surface after it's reflected.
The law of reflection says these two angles are equal.
<u>Answer:</u>
Alternating Current (AC).
<u>Explanation:</u>
The current that is provided to consumers in the United States changes direction sixty times a second. This household current is called alternating current (AC). Alternating current is much more efficient in transmitting electricity than direct current is. In order to produce this current, it is found in Alternating Current Power Plants.