A cyclist is travelling along a straight horizontal road. She is working at a constant rate of $$$150 \mathrm{~W}$$$. At an instant when her speed is $$$4 \mathrm{~m} \mathrm{~s}^{-1}$$$, her acceleration is $$$0.25 \mathrm{~m} \mathrm{~s}^{-2}$$$. The resistance to motion is $$$20 \mathrm{~N}$$$. Find the total mass of the cyclist and her bicycle. .................................................................................................................................................... .................................................................................................................................................... .................................................................................................................................................... .................................................................................................................................................... .................................................................................................................................................... .................................................................................................................................................... .................................................................................................................................................... .................................................................................................................................................... .................................................................................................................................................... .................................................................................................................................................... .................................................................................................................................................... ....................................................................................................................................................

Mathematics

IGCSE&ALevel

CAIE

Exam No：9709_s21_qp_43 Year：2021 Question No：2(a)

Answer:

Forward force exerted by cyclist $=\frac{150}{4} \mathrm{~N}[=37.5 \mathrm{~N}]$
\[
\frac{150}{4}-20=m \times 0.25
\]
\[
m=70 \mathrm{~kg}
\]

Knowledge points:

4.5.4 use the definition of power as the rate at which a force does work, and use the relationship between power, force and velocity for a force acting in the direction of motion Including calculation of (average) power;P = Fv

4.5.5 solve problems involving, for example, the instantaneous acceleration of a car moving on a hill

Answer:

Knowledge points:

Solution:

Related Question