Unitary Method
The word “unitary” comes from the word “unit”, which means a single and complete entity. In this method, we find the value of a unit product from the given number of products, and then we solve for the other number of products.
Speed, Time, and Distance
Imagine you and 3 of your friends are planning to go to the playground at 6 in the evening. Your house is one mile away from the playground and one of your friends named Jim must start at 5 pm to reach the playground by walk. The other two friends are 3 miles away.
Profit and Loss
The amount earned or lost on the sale of one or more items is referred to as the profit or loss on that item.
Units and Measurements
Measurements and comparisons are the foundation of science and engineering. We, therefore, need rules that tell us how things are measured and compared. For these measurements and comparisons, we perform certain experiments, and we will need the experiments to set up the devices.
A man 6 feet tall walks at a rate of 5 feet per second away from a light that is 15 feet above the ground. (a) When he is 10 feet from the base of the light, at what rate is the tip of his shadow moving? (b) When he is 10 feet from the base of the light, at what rate is the length of his shadow changing?
Given that:
A man 6 feet tall walks at a rate of 5 feet per second away from a light that is 15 feet above the ground.
Let x be the length of the base of the lamppost to the man.
a) When he is 10 feet from the base of the light, to find the at what rate is the tip of his shadow moving.
To use a proportion to find the shadow.
Let m be the length of the base of the lamppost to the shadow.
Let x be the length of the base of the lamppost to the man.
Then,
The length of the shadow is m - x.
But man is the 6 feet tall and lamppost is 15 feet tall.
To get,
15 m - 15 x = 6 m
Solve this equation for m,
Subtract on both side by 15 m,
- 15 x = - 9 m
Divide on both side by ( -9),
To get,
Step by step
Solved in 5 steps
