A- Straight Down
Remember wherever the object is, whether it is straight or inclined, gravitational pull will always act downwards.
B,
The 25 N and 5 N force are acting in the same direction so we can add them together, but the 10 N force acts in the opposite direction so you subtract it.
25 N + 5 N - 10 N = 20 N
Answer:
the rate of acceleration of the train is 4 m/s²
Explanation:
Given;
initial velocity of the train, u = 10 m/s
change in time of motion, dt = 5 s
final velocity of the train, v = 30 m/s
The rate of acceleration of the train is calculated as;

Therefore, the rate of acceleration of the train is 4 m/s²
Answer:
2,500,000 MJ (
)
Explanation:
According to the work-energy theorem:
The work done on an object is equal to the amount of energy transferred
In this problem, the energy transferred by the rocket is

Therefore, the work done must be equal to the energy transferred, therefore:

(a) The efficiency of an engine is defined as the ratio between the work done by the engine and the heat it takes in:

The engine in this problem does a work of

and it takes in

of heat, therefore its efficiency is

(b) The heat taken by the machine is 4000 J; of this amount of heat, only 1100 J are converted into useful work. This means that the rest of the heat is wasted. Therefore, the wasted heat is the difference between the heat in input and the work done by the engine: