Answer:
a. 652.68N
b. -2349.65J
c. -3116.12J
d. 5465.77J
e. Zero
Explanation:
a. According to equilibrium of forces, the force of gravity is equal to the sum of the frictional force and force exerted by the man in the opposite direction (since they're both resistant forces).
Fg = Fm + Fr
Fm = Fg - Fr
Fm = mgsin(28°) - umgcos(28°)
u = coefficient of frictional force.
Fm = 330*9.8*sin28 - 0.4*330*9.8*cos28
Fm = 1518.27 - 865.59
Fm = 652.68N
b. Work done by man is:
Wm = -Fm * d
Wm = -652.68 * 3.6
Wm = -2349.65J
c. Work done by friction force:
W(Fr) = -Fr * d
W(Fr) = -865.59 * 3.6
W(Fr) = -3116.12J
d. Work done by gravity:
Wg = Fg * d
Wg = 1518.27 * 3. 6
Wg = 5465.77J
e. Net work done on the piano is:
Work done by friction + work done by gravity + work done by man
= -3116.12 + 5464.77 + (-2349.65)
= 0J
Answer:
Their measured results are closer to the exact or true value. Hence, their measured value is considered to be more accurate.
Explanation:
Considering the situation described above, the accuracy of a measured value depicts how closely a measured value is to the accurate value.
Hence, since the students' measured values have very low percent differences, it shows the similarity of computations or estimates to the actual values, which in turn offers a smaller measurement error.
Therefore, their measured results are closer to the exact or true value, which implies that their measured value is considered to be more accurate.
Answer: Explanation:
Authors sometimes use an Unreliable Narrator to tell the story, a protagonist who can't be trusted to tell the events accurately. Either they are insane, evil, delusional, forgetful, or just plain wrong... whatever their reasons, the writer uses this technique to 'hook' the reader.
Hi!
The correct option would be C.
<h3>Explanation:</h3>
Scientific method is the protocol in an experiment for a hypothesis that involves testing, measurement, observation and necessary modification of hypothesis during the course of the experiment. There are several manners and experiments that can be tested for the hypothesis, and plenty of ways to design an experiment.
Scientific experiments can be very tricky to design, owing to the numerous parameters and variables that need to be accounted for. Of course, there are some relatively simple experiments. Creativity is needed for all branches of science, because each field presents obstacles in discovery, and creativity allows for us to devise ways around those obstacles. Science has always tested humans ability to think outside the box and question their surroundings, and creativity has been the driving force.
Hope this helps!
