Answer:
Explanation:
It is required that the weight of Joe must prevent Simon from being pulled down . That means he is not slipping down but tends to be towed down . So in equilibrium , force of friction will act in upward direction on Simon.
Let in equilibrium , tension in rope be T
For balancing Joe
T = M g
For balancing Simon
friction + T = mgsinθ
μmgcosθ+T = mgsinθ
μmgcosθ+Mg = mgsinθ
M = (msinθ - μmcosθ)
M = m(sinθ - μcosθ)
<u>Answer</u>
a) properties and hazards
<u>Explanation</u>
Having information on properties of a chemical helps you know the reactivity of that chemicals.
Most chemicals are very reactive. So you have to be away of their hazards to avoid accidents.
True because the neutrons are inside of the nucleus and the electron revolve around the nucleus