Physics Chapter 5 – Forces– speed and velocity Define the term speed and give the equation with units. On the graph calculate the speed of the cyclists between point A and B and D and E. A – B D – E Match the line to the correct diagram. The graph below shows a cyclists journey. Describe what is happening in the graph below: A-B B-C C-D D-E Work out the deceleration of the car and the distance it has travelled: Acceleration= change in velocity time taken Distance = area under the line Define the term velocity and give the units.

Physics Chapter 5 – Forces – acceleration, motion Define acceleration and deceleration. Give the equation for uniform motion and define the symbols below with units. s u v a A train approaching a red signal has a speed of 15m/s. the signal then changes and the train accelerates. By the time it has ravelled another 1500m. It is now travelling at 40m/s. What is its acceleration? Give the equation that links acceleration, velocity and time. State the units. Rearrange the equation for uniform motion to calculate a. Calculate the acceleration of a car when it increases its velocity to 50m/s from 10 m/s in 5 seconds. A ball is thrown vertically upwards at 12m/s. ignoring air resistance and taking g =9.8m/s2. Calculate how high it goes. Remember it will be momentarily stationary at the highest point so its velocity will be 0. Rearrange the equation for uniform motion to calculate a. Resultant force = √702 + 1102 = 130N Θ = tan-1(70 ÷  110) = 32o A car accelerates from 15m/s at 4m/s2 for the next 12m. What is its final velocity. s = u = v = a = Uniform motion is?

Physics Chapter 5 – Forces– forces, resultant forces, vectors What is a force? What are unbalanced forces and when do they occur? What are balanced forces and when do they occur? Define the terms scalar and vector. And give examples. HIGHER TIER- A box is pushed in an easterly direct with a force of 110N. The box is then pushed in a northern direction with a force of 70N. Calculate the resultant force. You will need to use Pythagoras’ theorem. Draw out the forces and show your working. From the above - calculate the direction. You will need to use trigonometry to determine the direction. Describe the difference between contact and non-contact forces and give examples of contact and non-contact forces. Calculate the resultant force acting on the below: 10N 9N 18N HIGHER TIER - Draw a free body diagram to show the force acting on a car accelerating, a tennis ball falling to the ground and an aeroplane traveling at a constant speed. Describe the difference between weight and mass. Resultant force = √702 + 1102 = 130N Θ = tan-1(70 ÷  110) = 32o Write the equation that links weight, mass and gravitational field strength. Give the units.

Physics Chapter 5 – Forces – Newton’s Laws of motion and inertia State Newton’s three laws of motion: 1. 2. 3. Calculate the force of an object that has an acceleration of 5m/s2 and a mass of 50kg. State how you convert from: g to kg cm to m Convert the below to the rightful form: 5cm 6g 800cm 95g 9000g 675g 89.6cm 95cm 9800cm 60.8g Calculate the mass of an object when the force acting on the object is 254N and the acceleration is 9m/s2. Explain using Newton’s first law of motion when the forces acting on an object will results in 0. Make reference to examples. HIGHER TIER – What is meant by the term inertia and inertial mass? Give the equation to calculate inertial mass. Give an example of an object that has a high inertial mass. Resultant force = √702 + 1102 = 130N Θ = tan-1(70 ÷  110) = 32o Calculate the acceleration of an object when the force acting on the object is 100N and the mass is 60kg. Write the equation that links force, mass and acceleration together.

Physics Chapter 5 – Forces –momentum, road safety and energy in a spring Define the terms: Reaction time Thinking distance Breaking distance Stopping distance Describe the dangers associated with a large deceleration. HIGHER TIER – Describe what momentum is and give the equation with units. Explain the conservation of momentum principle, include examples in your answer. If a sprinter with a mass of 50kg runs at a velocity of 10m/s what is their momentum? A 0.5 kg trolley is pushed at a velocity of 1.2 m/s into a stationary trolley with a mass of 1.5 kg. The two trolleys stick to each other after the impact. Calculate: The momentum of the 0.5 kg trolley before the collision The velocity of the two trolleys straight after the impact Sketch a graph to demonstrate Hook’s Law that shows there is a linear relationship between force and extension in a spring. Write the equation: 1. That links force, spring constant and extension and 2. Elastic potential energy, spring constant and extension. State what factors affect stopping distance. Resultant force = √702 + 1102 = 130N Θ = tan-1(70 ÷  110) = 32o Calculate the spring constant when a spring has an extension of 0.05m and is stretched by a force of 3N. State what factors can affect the breaking distance

Physics Chapter 5 – Forces – maths skill and 2 x required practical. Describe why estimates are useful. Describe a method used to investigate the acceleration of an object. Include a diagram of your set up. Describe a method used to investigate the relationship between force and the extension of a spring. Include a diagram of your set up. Significant figures are what? Round these numbers up or down: 0.56 78 100.1 0.05 189 Write the numbers below to 1 s.f. 11 10.2 56 Write the numbers below to 2s.f 123 89.51 156 Write the number below to 3 s.f. 1568 0.9874 10.39 Independent variable – Dependent variable – Control variables - Independent variable – Dependent variable – Control variables - Explain how this experiment follows Newton’s second law of motion. Write a risk assessment for this practical. Include the risk, hazard and control for at least 1 risk.