David Sang Solutions for Chapter: Forces and Motion, Exercise 8: End-of-chapter questions

An aeroplane is flying horizontally at a steady speed in a straight line. The diagram shows three of the four forces acting on it.
In order to fly horizontally at a steady speed, which two of the forces shown on the aeroplane must be equal?

An aeroplane is flying horizontally at a steady speed in a straight line. The diagram shows three of the four forces acting on it.
 in order to fly horizontally in a straight line, there must be a fourth force acting on the plane. Draw an arrow to represent this force.

The aeroplane flies an outward journey from Budapest (Hungary) to Palermo (Italy) in $2.75 \mathrm{hours}.$ The distance is $2200 \mathrm{km}.$ Calculate, the average speed of aeroplane.

The aeroplane flies an outward journey from Budapest (Hungary) to Palermo (Italy) in $2.75 hours$. The distance is $2200 km.$ On the return journey from Palermo to Budapest, the journey time is shorter, even though the engine thrust is the same. Suggest what might have caused the return journey to be shorter.

A young athlete has a mass of$42 kg$ . On a day when there is no wind, she runs $100 m$ race in $14.2 seconds$ . A sketch graph showing her speed during the race is.
The acceleration of the athlete during the first $3.0 second$ of the race.

A young athlete has a mass of $42 \mathrm{kg}$ . On a day when there is no wind, she runs a $100 \mathrm{m}$ race in $14.2 \mathrm{seconds}$. A sketch graph showing her speed during the race is given below. The accelerating force on the athlete during the first $3.0 \mathrm{seconds}$ of the race is:

A young athlete has a mass of $42 \mathrm{kg}$. On a day when there is no wind, she runs a $100 \mathrm{m}$ race in $14.2 \mathrm{s}$. A sketch graph showing her speed during the race is given.
Find the speed with which she crosses the finishing line.

A young athlete has a mass of $42 \mathrm{kg}$. On a day when there is no wind, she runs a $100 \mathrm{m}$ race in $14.2 \mathrm{s}$. A sketch graph showing her speed during the race is given.

Suggest two difference that might be seen in the graph if there had been a strong wind opposing the runners in the race.