Diameter = 60 cm, Radius = 60/2 = 30 cm = 30/100 = 0.3 m.
The pebble in the tread goes by 3 times every second.
This is the same as 3 times per second.
Recall the unit of frequency is Hertz or per second, s⁻¹
So 3 times per second, Frequency, f = 3s⁻¹ or 3 Hertz
For angular motion:
Angular speed, ω = 2πf
= 2*π*3
= 6π rad/s
Linear speed, v = ωr = 6π * 0.3 = 1.8π m/s
Linear acceleration, a = v² / r
a = 1.8π * 1.8π / 0.3 = 10.8π² m/s²
Angular acceleration α = a/r = 10.8π² / 0.3 = 36π² rad/s²
Angular speed = 6π rad/s ≈ 18.840 rad/s
The linear speed of the pebble = 1.8π m/s ≈ 5.655 m/s
The angular acceleration = 36π² rad/s² ≈ 355.306 rad/s²
The linear acceleration of the pebble = 10.8π² m/s ≈ 106.592 m/s²
From Utica, NY, Polaris can be observed is observed at an altitude of approximately 43° Which object represents a true scale model of the shape of the Earth? a) a Ping-Pong ball
Answer:
Explanation:
force of friction = μ mg
= .3 x 62 x 9.8
= 182.28 N
Work done by friction = 182.28 x 4.8
= 874.94 J
Energy loss by skier = 874.94 J
Kinetic energy after he passes the rough patch
= 1/2 x 62 x 6.8² - 874.94
= 1433.44 - 874.94
= 558.5 J
Velocity after crossing the patch v
1/2 x 62 x v² = 558.5
v² = 18
v = 4.2426 m /s
velocity at the bottom
v² = u² + 2gh
= 18 + 2 x 9.8 x 2.5
= 67
v = 8.18 m /s
b ) internal energy generated =
Work done by friction . = 874.94 J
Answer:
Which sentence best states the central idea of paragraphs 21-22 in "Energy Story"?
A. Materials that are insulators and conductors have a high
resistance to electricity.
Part B
Which sentence from "Energy Story" best supports the answer in Part A?
B. "Its resistance measures how well something conducts
electricity."
Explanation:
Electric potential differnce is defined as:
If we asume the electric field is constant we get:
We need to calculate the electic field strenght:
We can now calculate the potential difference:
