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1. A student was taking a rock-climbing class that used an indoor climbing wall. Before he started, the instructor asked for his weight. If the student had a mass of 88.6 kg, what was his weight? (2 points) Weight is the downward force of gravity, measured in Newtons, which is: F = m*g = 88.6kg * 9.81 m/s^2 = 869 N (3 s.f.) The equation above is Newton's 2nd Law of Motion where g is the acceleration due to gravity near the Earth's surface. 2. The student stood at the bottom of the wall and then started to climb the wall. Explain how :a. Newton's third law relates to the wall b. Newton's first law relates to the student (4 points: 2 points each part) the student exerts a force called action which is equal to its weight on the wall and the wall exerts an equal force called reaction onto the student standing in the opposite direction. 3. The same student was moving up the wall with an acceleration of 0.0003 m/s2. What was the force his muscles were using? (Hint: You will need the value of mass from question 1.) (2 points) ONLY ANSWER QUESTION 3 PLEASE... QUESTION 1 AND 2 ARE ALREADY ANSWERD

User Tomekwi
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The third question is the application of the second law of motion where the force exerted is the product of mass and acceleration:
F=ma
Where:
m=mass
a=acceleration

The mass in the first question is 88.6kg
The acceleration is given in the third which is 0.0003m/s^2

Just put that into the equation and you will get your force:
F=ma
F=(88.6kg)(0.0003m/s^2)
F=0.03kg.m/s^2 or 0.03N

The force exerted by the muslces is 0.03N.
User JacopKane
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