Define:
Force
Friction
Motion
State the formulae and SI units for: Speed, Acceleration, Force
Identify the Contact Forces
List the non-contact forces from question 5.
A student pushes a box with a force of 10 N, and it starts moving.
Explain why the box moved using the idea of balanced and unbalanced forces.
What would happen if the force applied was less than friction?
A cyclist travels 60 m in 10 s.
Calculate the speed.
Suggest one way the cyclist can increase speed.
A train suddenly stops due to an emergency brake. Identify Newton's law of motion responsible for the sudden jerk experienced by the passengers.
A ball rolling on grass slows down.
Identify the force responsible.
Explain how this force affects motion.
A boy skates at a velocity of 10 m/s and displaces to his east by 600 meters in 1 minute. Suggest the solution to cover double the distance in the same direction in the second minute. State the total distance and displacement after 2 minutes.
After traveling for 2 minutes towards east, he then travels back to the starting point at a speed of 30 m/s. Calculate the time he will take for his return journey. State the total distance and displacement of the boy after the entire travel.
The boy’s friend starts to skate at a speed of 5 m/s and then reaches 20 m/s after 3 mins. How much force would the friend having a mass of 30kg need to apply to increase the speed.
A delivery robot moves on two surfaces:
Smooth tiles
Rough carpet
The force required to be applied on the robot to move on a smooth surface is 2N. Select the correct suggestion if the same robot has to move on rough surface with constant speed.
A delivery truck must travel on an icy road where friction is extremely low.
Explain the problem the truck might face while moving or stopping.
Suggest two solutions to improve safety and control of the truck.
A cyclist finds difficult to ride bicycle on a beach than on a regular road.
Explain why it is difficult to ride on sand.
Suggest two design changes to improve movement.
A new high-speed elevator moves very quickly upward in a building.
Predict what might happen to passengers if the elevator suddenly stops.
Suggest one solution that can reduce the impact on passengers.
A new vehicle is designed to move on a planet where gravity is much weaker than Earth, and there is very little friction.
Predict how the motion of the vehicle will be different from that on Earth.
Suggest two ways engineers can control or stop the vehicle safely.
Study the data:
Surface | Distance (m) | Time (s) |
Smooth | 20 | 4 |
Rough | 20 | 8 |
Calculate speed for both surfaces.
Interpret the results.
A car’s motion is recorded:
Time (s) | Speed (m/s) |
0 | 0 |
2 | 4 |
4 | 8 |
6 | 8 |
Describe how the speed changes.
Identify the time from when the car stops accelerating.
An investigation is being designed to test following Research Question:
“How does surface type affect motion?” List the Variables for the experiment.
Independent
Dependent
Controlled
Roll a car on:
Smooth surface
Rough surface
Measure:
Distance travelled
Time taken
Trial | Distance (m) | Time on Smooth Surface (s) | Time on Rough Surface (s) |
1 | 10 | 2 | 4 |
2 | 20 | 4 | 8 |
3 | 30 | 5 | 10 |
Calculate speed for each trial on smooth surface.
Interpret the speed for each trial on a rough surface and outline the results with scientific reasoning.
Discuss validity of the method and describe enhancements / improvements
In this experiment it is predicted that, "toy car will take more time to travel the same distance on a rough surface than on a smooth surface as more friction is produced on the rough surface than on smooth surface".
Discuss the validity of this prediction
Identify variables here.
Explain: seatbelts are important for the safety of passengers.
Comment: friction is both useful and harmful
Numericals
A runner travels 100 m in 10 s. Calculate the speed.
A bike speeds up from 5 m/s to 15 m/s in 5 s. Calculate acceleration.
Mass = 4 kg, acceleration = 3 m/s² in the east.
Calculate the value and list the direction of the force acting on the body.
State the direction of the frictional force acting on the child while sliding down a slide in children park.
Explain: All the objects fall towards the ground in the earth’s atmosphere.
State the relationship of the force acting on the falling object with the mass of the object, mass of earth and the distance between the object and ground.
Justify: A ball rolling on ice will stop later than a ball rolling on football turf.
Verify: It requires more effort to push a heavy object than a lighter one.
Recall the two forces which have the greatest impact on daily life.
Interpret the solution suggested in the video to improve transport systems.
Evaluate the solution suggested in the video to improve transport systems.
Deduce from the given information and predict the probability of application of the suggested solution.