Answer:
a) 2.41 km
b) 38.8°
Questions c and d are illegible.
Explanation:
We can express the displacements as vectors with origin on the point he started (0, 0).
When he traveled south he moved to (-3, 0).
When he moved east he moved to (-3, x)
The magnitude of the total displacement is found with Pythagoras theorem:
d^2 = dx^2 + dy^2
Rearranging:
dy^2 = d^2 - dx^2
The angle of the displacement vector is:
cos(a) = dx/d
a = arccos(dx/d)
a = arccos(3/3.85) = 38.8°
Answer: Neon is a colorless gas at room temperature: Physical property
At room temperature, mercury is a liquid: Physical property
Apple slices turn brown when exposed to air: Chemical property
Phosphorus will ignite when exposed to air: Chemical property
Explanation:
Physical property is defined as the property of a substance which becomes evident during physical change in which there is alteration in shape, size etc. No new substance gets formed during physical change.
Example: Neon is a colorless gas at room temperature
At room temperature, mercury is a liquid.
Chemical property is defined as the property of a substance which becomes evident during chemical change in which a change in chemical composition takes place. A new substance is formed in these reactions.
Example: Apple slices turn brown when exposed to air: It undergoes oxidation which is a chemical change
Phosphorus will ignite when exposed to air: It undergoes oxidation which is a chemical change
Answer
Any force greater 490N
Explanation
The force required just to make an object slide over a rough horizontal surface is any force greater that the static friction which given by;
Given;
Hence;
F = 0.5 x 100 x 9.8
F = 490N.
We will only need the coefficient of kinetic friction if we were asked to find the force required to keep the object moving uniformly. Usually, the force needed to keep an object moving uniformly over a rough surface is lesser that which is needed to start its motion.
In this problem, we were only asked to find the minimum force required to make the object move which we have done.
Because a liquid can take the wheight of the hydraulic press while a gas could combust under pressure.
Answer:
<em>The amount of water in circulation is the same</em>
Explanation:
The water cycle is the pathway in which water moves from the atmosphere to the earth and back to atmosphere ones again.
During the sunny period, the temperature of the earth is heated up, water evaporates to the atmosphere as water vapour. The water vapour gathers as cloud and comes back to the earth as rain, which enters our rivers and stream. Thereby maintaining a continuous cycle.
With the water cycle, the movement of water via precipitation and evaporation is the same on earth.
