Answer:
True
Explanation:
Limestone is a carbonate chemical sedimentary rock often chemically called calcium carbonate.
The mineral calcium carbonate makes up the framework of this rock that has become the staple material used for cement production.
Chemically, the formula is given as CaCO₃. The rock accumulates from the a rich deposit of calcite, which is the mineral that is made up of calcium carbonate to form the limestone.
CaCO₃ - Calcite - Limestone
compound mineral rock
Limestone is a rock and the compound it is made up of is calcium carbonate. In some cases, a Ca-Mg carbonate occurs with limestone and it is called a dolomite.
This matter is called medium
Answer:
Due to potential difference (elaborated in explanation)
Explanation:
When a bird sits on a power line, its whole body is in contact with the power line. It does not have any contact with the ground or anything at a lower potential. Hence, the current does not flow through the bird's body, because there is no potential difference available as a driving force.
Now, when a person touches the power line his hand is at a higher potential provided by the power line, while the rest of his body is connected to the ground, usually through legs. The current always looks for a path from high potential to low potential. Therefore, the body of the person serves as the path for the current. Heavy current flows through the body and the person dies within split seconds.
Answer:
a) 17 N
b) 21 N
Explanation:
At the 3 o'clock position, the sum of the forces towards the center is:
∑F = ma
T = m v² / r
19 = m v² / r
At the 12 o'clock position, the sum of the forces towards the center is:
∑F = ma
T + mg = m v² / r
T + (0.18)(9.8) = 19
T = 17.2 N
At the 6 o'clock position, the sum of the forces towards the center is:
∑F = ma
T − mg = m v² / r
T − (0.18)(9.8) = 19
T = 20.8 N
Rounding to two significant figures, the tensions are 17 N and 21 N.
Force, work
Force may be exerted constantly but until there is displacement in the direction of the force, no work is done.
