In an undeveloped country, the rural areas will often be off the grid, with no access to consistent electricity. For a household living in this situation, <u>wood</u> would most likely be used to heat the home in the winter.
<u>Explanation:</u>
With the help of wood, we can burn it and make fire to heat the house in winter. In the earlier days, wood was used to produce heat and was used for cooking and other purposes.
So when a rural area does not have electricity,stoves would be fired with either biomass fuels, such as wood, branches, twigs or dung, or coal. Also for heating the home, the same would be used. These fuels are collected from the local environment in rural areas and purchased through markets in urban areas. Even now in some countries like India and China use wood or any other biomass fuel for heating and cooking.
Net force also known as an Unbalanced force.
To solve letter a:
d1 = 85t1 = 16 km,
85t1 = 16,
t1 = 16 / 85 = 0.1882 h = 11.29 min.
d2 = 115t2 = 16 km,
115t2 = 16,
t2 = 16 / 115 = 0.139 h = 8.35 min.
t1 - t2 = 11.29 - 8.35 = 2.94 min.
Car #2 arrives 2.94 minutes sooner.
To solve letter b:
15 min = 1/4 h = 0.25 h.
d1 = d2,
115t = 85(t + 0.25),
115t = 85t + 21.25,
115t - 85t = 21.25,
30t = 21.25,
t = 21.25 / 30 = 0.71 h,
d = 115 * 0.71 = 81.65 km.
Q 24: Newton's first law of motion states that anything that stands still will stay still unless unbalanced force is acted upon that object. Newton's second law of motion states that the velocity of an object changes when subjected to external Force. Newton's third law of motion says that for every action there is an equal and opposite reaction. when bumper cars crash into each other one car goes one way and the other goes the other way.
Q 25: if the bumper cars doubled their Mass the motion would be halfed but if the net force is doubled the motion will double.
Answer:
a = 0
Explanation:
The velocity of a sound wave in a straight line is 660 mph. The wave is moving with a constant velocity. It means that the change in velocity is equal to 0.
We know that acceleration of an object is equal to the change in velocity divided by time taken. But here the change in velocity is 0. As a result the acceleration of the sound wave is 0.
