2025 Montfort Physics Formula List 6091

SYLLABUS 6091 PHYSICS G3 YEAR 2024LIST OF EQUATIONS NO. EQUATION MEANING OF SYMBOLS Example Solution GENERAL PHYSICS 1 a = Δ v / Δ t = (v – u) / t a = instantaneous acceleration in m/s2 ; v = final velocity ; u = initial velocity ; t = time taken in s A car accelerates uniformly from 20 m/s to 30 m/s. During this acceleration, the car travels 100m. The average speed is 25 m/s. What is the acceleration of this car? ** t = 4.0 s in this question based on formula (3) average speed. = 2.5 m/s2 2 Distance travelled = area under graph The graph represents the movement of a car. How far has the car moved between 0 and 5.0 s? Distance travelled = area under graph = ½ x 5.0 x 10 = 25 m 3 A car takes half an hour to travel 7.0 km from A to B. What is its average speed? = 14 km/h4 F = ma Fresultant = Fapplied – Fopposing resultant is also known as netfriction, air resistance are possible FopposingF = resultant force in N ; m = mass in kg ; a = acceleration in m/s2 A boy pushes a box of mass 20 kg with a force of 50 N at constant speed. When the force is increased to 80N, what is the acceleration of the box? Frictional force = 50 N Resultant force = 80 N – 50 N F = ma 80 – 50 = 20 (a) a = 1.5 m/s2

5 ρ ρ = density in kg/m3 ; m = mass in kg ; V = volume in m3 Given that a wooden cube of length 8.0 cm has a mass of 500 g, calculate the density of the wood in g cm-3. ρ = 0.97656 ≈ 0.98 or 0.977 g / cm3 6 w = mg w = weight in N ; m = mass in kg ; g = gravitational field strength in N/kg The acceleration of free fall on the Moon is 1.6 ms-2. The acceleration of free fall on Earth is 10 ms-2. A rock has a mass of 10 kg on Earth. Calculate the weight of the rock on (a) on Earth (b) on the Moon. (a)w = mg = (10)(10) = 100 N (b)w = mg = (10)(1.6) = 16 N 7 Moment = F x d F = force in N ; d = perpendicular distance from the line of action of F to the pivot in m A door is hinged at its edge. A girl opens it by exerting a force of 10 N on the door handle located at the other end. Determine the moment due to the force exerted by the girl on the door. Moment = F × d = 10 N × 1.0 m = 10 N m 8 W = F x s [use if F is constant] W = work done in J ; F = force in N ; s = distance moved in the direction of F in m A boy pushes a box across a rough horizontal floor. He exerts 5.0 N to move it 2.0 m. What is the work done by the 5.0 N force? W = F × s = 5.0 x 2.0 = 10 J 9 P orP P = power in W ; W = work done in J ; t = time in s ; E = energy converted An engine does 60 000 J of work in ten minutes. Determine its power. * 1 W = 1 J/s so the time must be expressed in seconds for it to be converted to Watts (W)P = 100 W 10 Ep = mgh Ep = energy in gravitational potential store in J ; m = mass in kgg = 10 N/kg gravitational field strength on earth; h = vertical distance in m A 5.0 kg box is raised 50 m from its original