Pop Quiz:
1) What is the derivative of cos(x)?
2) What is the 45 degrees in radians?
3) Remember the cosine of 45 degrees?
4) Can you convert kilometers to miles?
5) Which two sides of a right triangle are used to calculate tangent?
6) Is displacement a vector or a scalar?
7) An object is launched into the air at an angle of 60 degress with respect to the horizontal. What are the velocities in the x and y directions?
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ANSWER ALERT!!!
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So, how did you do??? Here are the answers:
1) What is the derivative of cos(x)?: The answer is -sin(x). We haven't quite covered it here yet, but the derivatives of trig functions are essential for doing well in Physics.
2) What is the 45 degrees in radians?: The answer is pi/4. We can calculate this by multiplying 45 * pi/180 = pi/4.
3) Remember the cosine of 45 degrees?: The answer is sqrt(2)/2. We can remember this by reviewing Episode 24: Sines and Cosines by Counting to 4 episode of the podcast.
4) Can you convert kilometers to miles?: 1km = 0.621mi. If you know that there are roughly 1.6 km in a mile, we can use a conversion factor to solve: 1 km * 1 mi/1.6 km = 0.621mi.
5) Which two sides of a right triangle are used to calculate tangent?: Recalling sohcahtoa, we can use TOA, or tangent = opposite/adjacent to answer this question.
6) Is displacement a vector or a scalar? Displacement is a vector quantity, while distance is a vector, as it does not include a direction.
7) An object is launched into the air at an angle of 60 degress with respect to the horizontal. What are the velocities in the x and y directions?: This is a matter of breaking our velocity vector into components. We're not given a velocity so we can use a generic velocity v. vx = v*cos(60) = v/2 and vy = v*sin(60) = v*sqrt(3)/2.
So how did you do? This is a 7 question quiz. Each question was taken from a single app from the Physics Brush Up app bundle. Calculus. Radians vs. Degrees. Sin vs. Cosine. Unit Conversion. Sohcahtoa. Vectors vs. Scalars. Vector Components. If you were shaky on more than one question, you should consider grabbing it. You'll thank yourself later!
