Mechanics - Motion in a Plane - SS2 Physics Past Questions and Answers - page 3
A projectile is launched at an angle of 45 degrees with the horizontal. At the highest point of its trajectory, the projectile's velocity and acceleration vectors are:
Both horizontal
Both vertical
Velocity horizontal, acceleration vertical
Velocity vertical, acceleration horizontal
A car is travelling along a curved road. Which of the following forces acts as the centripetal force to keep the car in its curved path?
Gravitational force
Frictional force between the tires and the road
Normal force
Air resistance
A roller coaster starts at the top of a hill and then descends. As the coaster descends, its gravitational potential energy:
Increases
Decreases
Remains constant
Depends on the speed of the coaster
A gymnast performing on uneven bars swings back and forth. At the highest point of each swing, the gymnast's acceleration is:
Maximum
Minimum
Zero
Cannot be determined
A boat is crossing a river with a current. To reach the opposite shore directly across, the boat must be aimed:
Straight upstream
Straight downstream
Upstream and at an angle
Downstream and at an angle
Explain the concept of projectile motion and its applications in real-life scenarios.
Projectile motion refers to the motion of an object that is launched into the air and moves along a curved path under the influence of gravity. This concept finds various applications in real-life situations. One such application is in sports, such as throwing a ball or shooting a projectile in sports like baseball or archery. Projectile motion is also crucial in fields like engineering, where the trajectory of a rocket or a missile needs to be accurately determined. Additionally, understanding projectile motion is essential in physics research, as it helps in studying the motion of particles or projectiles in experimental setups.
Discuss the importance of centripetal force and its applications in circular motion.
Centripetal force is the force that acts towards the centre of a circular path, keeping an object moving in uniform circular motion. It has numerous applications in real-life scenarios. One of the prominent applications is in the field of transportation, specifically in vehicles taking turns on curved roads.
The centripetal force provided by friction between the tires and the road enables the vehicle to follow the curved path without sliding or skidding. Another important application is in amusement park rides like roller coasters and Ferris wheels, where centripetal force is responsible for keeping the riders moving in circular paths. Moreover, understanding centripetal force is vital in designing and analysing the behaviour of machines like centrifuges used in laboratories and industrial processes.