The answer is letter C. <span>A train travels from the bottom of a hill to the top of a hill, its moves slower by the time it reaches the top is an example of negative acceleration.
In physics, acceleration can be described as an objects change of velocity. When an object gains velocity, it is positive acceleration, and negative acceleration for the opposite.
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Answer:
Time of flight A is greatest
Explanation:
Let u₁ , u₂, u₃ be their initial velocity and θ₁ , θ₂ and θ₃ be their angle of projection. They all achieve a common highest height of H.
So
H = u₁² sin²θ₁ /2g
H = u₂² sin²θ₂ /2g
H = u₃² sin²θ₃ /2g
On the basis of these equation we can write
u₁ sinθ₁ =u₂ sinθ₂=u₃ sinθ₃
For maximum range we can write
D = u₁² sin2θ₁ /g
1.5 D = u₂² sin2θ₂ / g
2 D =u₃² sin2θ₃ / g
1.5 D / D = u₂² sin2θ₂ /u₁² sin2θ₁
1.5 = u₂ cosθ₂ /u₁ cosθ₁ ( since , u₁ sinθ₁ =u₂ sinθ₂ )
u₂ cosθ₂ >u₁ cosθ₁
u₂ sinθ₂ < u₁ sinθ₁
2u₂ sinθ₂ / g < 2u₁ sinθ₁ /g
Time of flight B < Time of flight A
Similarly we can prove
Time of flight C < Time of flight B
Hence Time of flight A is greatest .
To solve this problem it is necessary to apply the concepts related to momentum, momentum and Force. Mathematically the Impulse can be described as

Where,
F= Force
t= time
At the same time the moment can be described as a function of mass and velocity, that is

Where,
m = mass
v = Velocity
From equilibrium the impulse is equal to the momentum, therefore


PART A) Since the body ends at rest, we have the final speed is zero, so the momentum would be



Therefore the magnitude of the person's impulse is 1125Kg.m/s
PART B) From the equation obtained previously we have that the Force would be:



Therefore the magnitude of the average force the airbag exerts on the person is 45000N
Answer:
(i) W = 8.918 N
(ii) 
(iii) d = 9.1 cm
Explanation:
Part a)
As we know that weight of cube is given as


here we know that



now the mass of the ice cube is given as

now weight is given as

Part b)
Weight of the liquid displaced must be equal to weight of the ice cube
Because as we know that force of buoyancy = weight of the of the liquid displaced

So here volume displaced is given as



Part c)
Let the cube is submerged by distance "d" inside water
So here displaced water weight is given as



so it is submerged by d = 9.1 cm inside water