Answer:
<h3>⭐Application of heat to certain substances causes only physical changes in which no new substance or substances are formed. Application of heat to some substances causes chemical changes, or chemical reactions, in which one or more new substances are formed, with different properties from the original.</h3>
Answer:
The question is incomplete.the complete question is giving below "College Physics 10+5 pts
Your bedroom has a rectangular shape, and you want to measure its area. You use a tape that is precise to 0.001 and find that the shortest wall in the room is 3.547 long. The tape, however, is too short to measure the length of the second wall, so you use a second tape, which is longer but only precise to 0.01 . You measure the second wall to be 4.79 long. Which of the following numbers is the most precise estimate that you can obtain from your measurements for the area of your bedroom?
A. 17.0m^2
B. 16.990m^2
C.16.99m^2
D.16.9m^2
E. .16.8m^2
b. If your bedroom has a circular shape, and its diameter measured 6.32 , which of the following numbers would be the most precise value for its area?
a)30 m^2
b) 31.4 m^2
c)31.37 m^2
d)31.371 m^2
Answers:
A. 17.0m²
B. 31.4m²
Explanation:
First, we determine the area of the room using the measured parameters I.e
Length=4.79 long
Breadth= 3.547 long
Hence area is calculated as
A=length *Breadth
A=4.79*3.547
A=16.99013m²
From the question the different measurements have different precision, the answer should match the number of significant figures of the least precisely known number in the calculation which is 3 significant digits.
Hence the correct answer will be 17.0m²
B. The are of a circle is express as
A=πd²/4
A=π(6.32)²/4
A=31.37069m²
The π and 4 are exact number they have no effect on the accuracy on the accuracy of the area. Hence we express the answer to the same significant figure as giving in the question..
The correct answer will be 31.4m²
The question is incomplete. Here is the entire question.
A jetboat is drifting with a speed of 5.0m/s when the driver turns on the motor. The motor runs for 6.0s causing a constant leftward acceleration of magnitude 4.0m/s². What is the displacement of the boat over the 6.0 seconds time interval?
Answer: Δx = - 42m
Explanation: The jetboat is moving with an acceleration during the time interval, so it is a <u>linear</u> <u>motion</u> <u>with</u> <u>constant</u> <u>acceleration</u>.
For this "type" of motion, displacement (Δx) can be determined by:

is the initial velocity
a is acceleration and can be positive or negative, according to the referential.
For Referential, let's assume rightward is positive.
Calculating displacement:


= - 42
Displacement of the boat for t=6.0s interval is
= - 42m, i.e., 42 m to the left.
Answer:
A
Explanation:
Hope this helps and have a wonderful day!!!