Answer: D
Explanation:
When an object falls gravity is pulling down on it and is picking up speed, but as it gains speed air resistance becomes a faster. Air resistance increases with speed. And that force keeps it from accelerating eventually the object will pick up speed such that the force due to air resistance will keep it from getting any more speed at that point force due to air resistance is equal to its weight (mg) and the net force is equal to zero so it won’t accelerate any more at that point it is said to be moving in terminal velocity.
When an object has reached terminal velocity, it will have a constant velocity
Answer:
37.33m
Explanation:
Using the equation of motion
S = ut + 1/2gt^2
Time t = 2.76secs
g = 9.8m/s^2
S = 0 + 1/2(9.8)(2.76)^2
S = 4.9*7.6176
S = 37.33
Hence the window is 37.33m above the ground
Weight = (mass) x (gravity)
120 N = (mass) x (9.8 m/s²)
Mass = (120 N) / (9.8 m/s²)
Mass = 12.24 kg (B)
Answer
given,
length of slender rod =80 cm = 0.8 m
mass of rod = 0.39 Kg
mass of small sphere = 0.0200 kg
mass of another sphere weld = 0.0500 Kg
calculating the moment of inertia of the system



using conservation of energy




we know,
v = r ω


v = 1.084 m/s
This can be seen as a trick question because heat engines can typically never be 100 percent efficient. This is due to the presence of inefficiencies such as friction and heat loss to the environment. Even the best heat engines can only go up to around 50% efficiency.