placing a magnetically hard material in a strong magnetic field
Answer:
Explanation:
Given:
length of ladder 
weight of ladder 
position of firefighter 
weight of firefighter 
angle of ladder 
Unknown:
force of the wall on the ladder 
force of friction on base of ladder 
normal force on base of ladder 
From the free body diagram of the sketch you get 3 equations:
Solving the equations gives:
a)
b)
c) Using the result from b and solving for 
Answer:
d- Earth revolves around the sun.
Explanation:
Earth rotation can be defined as the amount of time taken by planet earth to complete its spinning movement on its axis.
This ultimately implies that, the rotation of earth refers to the time taken by earth to rotate once on its axis. One spinning movement of the earth on its axis takes approximately 24 hours to complete with respect to the sun.
On the other hand, earth revolution can be defined as a complete trip along a path around the sun. This path is known as an orbit and it typically takes the Earth 365¼ days to complete it's journey around the Sun.
When a constellation (stars) changes its position in the sky, at the same time of the evening and over a period of several weeks; it ultimately implies or is an evidence that Earth revolves around the sun.
C Weight is the gravitational pull on an object
Heat supplied to the gold will raise the temperature of the gold from 20 degree Celsius to 90 degree Celsius.
Mass of the gold (m) = 0.072 kg
Temperature change (ΔT) = 90 - 20 = 70 degree Celsius
Specific heat capacity of the gold (c) = 136 J/kg C
Heat supplied = m × c × ΔT
Heat supplied = 0.072 × 136 × 70
Heat supplied = 685.44 Joules
Hence, the heat supplied to the gold to raise the temperature from 20 degree Celsius to 90 degree Celsius = 685.44 Joules
