Forces Movement Shape And Momentum
A tennis player strikes a stationary ball with a racket. Which row correctly identifies all the effects of the force on the ball during contact?
Which type of force causes a charged balloon to stick to a neutral wall?
A runner completes exactly two full laps of a 200 m circular track, returning to the starting point. What are the distance travelled and the displacement of the runner?
A boat engine produces a forward thrust of 3200 N. Water resistance acts at 2100 N and wind resistance acts at 600 N, both opposing the motion. What is the resultant force on the boat?
A crate is pushed to the right across a rough floor at constant velocity. Which statement correctly explains why a force must continue to be applied?
A car of mass 1200 kg accelerates uniformly from rest to 90 km/h in 10 s. Calculate the resultant force acting on the car.
An astronaut has a mass of 75 kg. On the Moon, where g = 1.6 N/kg, her weight is 120 N. Which statement about the astronaut on Earth (g = 9.8 N/kg) is correct?
A car travels at 30 m s⁻¹. The driver’s reaction time is 0.7 s, and the braking distance at this speed is 75 m. What is the stopping distance?
A car’s speed is doubled from 15 m s⁻¹ to 30 m s⁻¹. Assuming the same braking force and driver reaction time, by what factor does the braking distance increase?
A skydiver has just reached terminal velocity. Which statement correctly describes the forces acting?
In an investigation of how extension varies with applied force for a helical spring, a student finds the spring does not return to its original length after the masses are removed. What does this indicate?
A spring has a spring constant of 50 N/m. What force is required to produce an extension of 24 cm?
A 0.40 kg ball moves to the right at 8.0 m s⁻¹ and strikes a wall, bouncing back to the left at 6.0 m s⁻¹. Taking rightward as positive, what is the change in momentum of the ball?
A 1500 g toy truck travelling at 2.0 m s⁻¹ to the right collides with and sticks to a stationary 500 g toy car. Calculate the velocity of the combined objects after the collision.
A passenger wearing a seatbelt in a car crash decelerates from 14 m s⁻¹ to rest. The passenger’s mass is 80 kg. With the seatbelt, the stopping time is 0.50 s. What is the magnitude of the average force on the passenger?
A mountain climber at high altitude is found to have an elevated red blood cell count compared to a person at sea level. Which explanation correctly accounts for this observation?
A swimmer pushes backward on the water with a force of 120 N. According to Newton’s third law, which statement correctly describes the reaction force?
A uniform beam of length 2.0 m and negligible weight is supported at both ends, P and Q. A 600 N load is placed 0.50 m from end P. What is the support force at end Q?
A person applies a force of 60 N at the end of a door handle located 0.75 m from the hinges. A second person pushes on the same door at a point 0.25 m from the hinges. What force must the second person apply to produce the same moment about the hinges?
A book rests on a table. A student identifies the weight of the book (downward) and the normal contact force from the table (upward) as a Newton’s third law pair. Why is this identification incorrect, and which force is the correct third law partner of the book’s weight?