2021-May-Physics_paper_1__TZ2_HL – All Questions with detailed solution
Q.1.2021-May-Physics_paper_1__TZ2_HL
Topic: Uncertainties and errors
Given: A student measures the length l and width w of a rectangular table top.
Calculate: What is the absolute uncertainty of the perimeter of the table top?
A. $0.3 \mathrm{~cm}$
B. $ 0.6 \mathrm{~cm}$
C. $ 1.2 \mathrm{~cm}$
D. $2.4 \mathrm{~cm}$
Answer/Explanation
Solution:
Absolute uncertainty in perimeter $=\Delta P=\pm 2(\Delta w+\Delta l)$
$
\begin{aligned}
& =\pm 2 \times(0.2+0.1) \\
& =\pm 2 \times(0.3) \\
& =\pm 0.6 \mathrm{~cm}
\end{aligned}
Q.2.2021-May-Physics_paper_1__TZ2_HL
Topic: Motion
Given: The minute hand of a clock hanging on a vertical wall has length L = 30 cm.
The minute hand is observed pointing at 12 and then again 30 minutes later when the minute hand is pointing at 6.
Calculate: What is the average velocity and average speed of point P on the minute hand during this time interval?
Answer/Explanation
Solution:
Average velocity $=\frac{\text { total displacement }}{\text { total time }}$
Total displacement in this interval is $2 \mathrm{~L}$
$
\left\langle v_{a v g}\right\rangle=\frac{2 L}{30 \min }=\frac{2 \mathrm{~cm}}{\min }
$
Speed $_{\text {avg }}=\frac{\text { total distance }}{\text { total time }}$
Total distance in this interval is $\pi L$
Q.3.2021-May-Physics_paper_1__TZ2_HL
Topic: Forces
Given: A block rests on a rough horizontal plane. A force P is applied to the block and the block moves to the right.
There is a coefficient of friction $\mu_d$ giving rise to a frictional force F between the block and the plane.
Calculate: If force P is doubled. Will $\mu_d$ and F be unchanged or greater?
Answer/Explanation
Solution:
The coefficient of static frictional force depends upon the nature of the surfaces in contact and on their roughness.
And $\mathrm{F}=\mu \text{N}$ and $\text{N=Weight of body}$
Q.4.2021-May-Physics_paper_1__TZ2_HL
Topic: Motion
Given: A projectile is launched at an angle above the horizontal with a horizontal component of velocity $V_h$ and a vertical component of velocity $V_v$. Air resistance is negligible.
Discuss: Which graphs show the variation with time of $V_h$ and of $V_v$ ?
Answer/Explanation
Solution:
Q.5.2021-May-Physics_paper_1__TZ2_HL
Topic: Forces
Given: A person with a weight of 600 N stands on a scale in an elevator.
Calculate: What is the acceleration of the elevator when the scale reads 900 N?
A. $5.0 \mathrm{~ms}^{-2}$ downwards
B. $1.5 \mathrm{~m} \mathrm{~s}^{-2}$ downwards
C. $1.5 \mathrm{~m} \mathrm{~s}^{-2}$ upwards
D. $5.0 \mathrm{~m} \mathrm{~s}^{-2}$ upwards
Answer/Explanation
Solution:
Scale reads only the Normal reaction acting on it, so by free body diagram
$\text { Acceleration }=\frac{900-600}{60}=5 \mathrm{~ms}^{-2}$