The correct answer to this question is C - Gravity is a force. Gravity
is also an example of a universal law. Well, according to Isaac Newton,
anyway. According to Newton's Law of Universal Gravitation, 'every point
mass attracts every single point mass by a force pointing along the
line intersecting both paths.'
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Here the block has two work done on it
1. Work done by gravity
2. Work done by friction force
So here it start from height "h" and then again raise to height hA after compressing the spring
So work done by the gravity is given as

Now work done by the friction force is to be calculated by finding total path length because friction force is a non conservative force and its work depends on total path


Total work done on it

So answer will be
None of these
Answer:
m = 2218.67 kg
Explanation:
It is given that,
Initial velocity, u = 7.5 m/s
Final speed of an object, v = 0 (at rest)
Force, F = 5.2 kN
Time, t = 3.2 s
We need to find the mass of the object. Force acting on an object is given by :
F = ma
m is mass, a is acceleration

So, the mass of the object is 2218.67 kg
Answer:
Speed of wind = 50mi/hr, Speed of plane in still air = 400mi/hr
Explanation:
Let the speed of the wind = Vw,
Speed of the plane in still air = Vsa,
The first trip the average speed of the plane = 1575mi/4.5hours = 350mi/hr
The coming trip the wind behind = 1575mi/3.5hrs = 450
Write the motion in equation form
First trip ( the plane flew into the wind)
Vaverage = Vsa - Vw
350 = Vsa - Vw
Second trip the wind was behind
450 = Vsa +Vw
Adding the two equation
800 = 2Vas
Vas = 800/2 = 400mi/hr
Substitute for Vas into equation 1
350mi/hr = 400mi/hr - Vw
Vw = 400-350 = 50mi/hr
Initial speed of Gazelle is along x direction and its value will be

also its initial height is given as

Part a)
now from kinematics along Y direction

as we know that





Part b)
distance moved horizontally

as we know that

now we will have

so it will lend at distance of 4 m.
Part c)
final velocity in vertical direction



so net speed will be


