Answer: Option D

Refer to this MCQ from PurePhysics 2015P1Q6 Answer: Option C

(1) (2) (3) (4)

Vector diagram is commonly referred to parallelogram diagram . Vector diagrams are generally divded into 3 categories: 1) 2 forces acting on a body, there is a resultant force. (Newton’s 2nd Law) 2) 3 forces acting on a body, the body is at rest / in equilibrium or moving at constant speed . (Newton’s 1st Law, Net force = 0N)  – The resultant force due to any 2 forces is equal and opposite to the 3rd unknown force. 3) 3 forces acting on a body, the body is at rest / in equilibrium or moving at constant speed (Newton’s 1st Law, Net force = 0N)    – Only 1 known force, angles given, using closed loop triangle to find the 2 unknown forces. Let’s look at some examples for each category. 1) 2 forces acting on a body, there is a resultant force. (Newton’s 2nd Law) 2) 3 forces acting on a body, the body is  at rest / in equilibrium  or moving at  constant speed . (Newton’s 1st Law, Net force = 0N) – The resultant force due to any 2 forces is equal and opposite to the 3rd unknown force. – You can either use  parallelogram rule  or  closed looped triangle . Example 1: Body at rest – Using Parallelogram Rule Example 1: Body at rest – Using Closed-Looped Triangle Example 2: Body at constant speed – Using Parallelogram Rule Example 2: Body at constant speed – Using Closed-Looped Triangle 3) 3 forces acting on a body, the body is  at rest / in equilibrium  or moving at  constant speed  (Newton’s 1st Law, Net force = 0N)     – Only 1 known force, angles given, using closed loop triangle to find the 2 unknown forces. Example 1 Example 2

For Combined Science (Physics), drawing of vector diagram is a must.In general, two known forces are given and the resultant force of these two forces is to be found using the vector diagram . There are two methods to draw vector diagram 1) Parallelogram method and 2) Tip-to-tail method.  In this post, the parallelogram method is used.

On the nuclear trail: The dawn of a global renaissance in nuclear energy (Source: Strait Times 19 Oct 2024) https://www.straitstimes.com/multimedia/graphics/2024/10/nuclear-energy-global-renaissance/index.html?shell Image source: ChatGPT

On earth, the gravitational field strength is 10 N/kg and the acceleration due to gravity is 10 ms-2 . That means when you release an object from you hand, the object will fall with increasing speed. The acceleration is a constant 10 ms-2 (acceleration due to gravity). Simply put, it means in 1 second, the speed of the object will increase by 10 m/s. In general, if there is no air resistance or air resistance is negligible , the speed-time graph is a straight line with constant gradient and passes through origin, i.e. speed is directly proportional to the time. If there is air resistance , there is a maximum constant speed if the object continues to fall. Hence the graph is different. More importantly, remember that any object that you released on earth, whether there is air resistance or no air resistance, the initial acceleration when it is released is always a constant 10 ms-2! Refer to the video for the explanation and some examples.

When a ball is thrown up vertically from a height and the falls to the ground, the various kinematic graphs below shows the same motion of the ball. Fixing up as positive, if the ball is going up, it’s displacement and velocity will be in the positive region. When it falls, the direction is opposite, hence it’s in the negative portion. Recall that the gradient of a velocity-time graph represents the acceleration. Using this concept, it will be easier to understand that the acceleration is a negative constant acceleration, thus – 10 ms-2. (acceleration is 10 ms-2 downwards towards earth)