Answer:
1977.696 J
Explanation:
Given;
Weight of the box = 28.0 kg
Force applied by the boy = 230 N
angle between the horizontal and the force = 35°
Therefore,
the horizontal component of the force = 230 × cosθ
= 230 × cos 35°
= 188.405 N
Coefficient of kinetic friction, μ = 0.24
Force by friction, f = μN
here,
N = Normal force = Mass × acceleration due to gravity
or
N = 28 × 9.81 = 274.68 N
therefore,
f = 0.24 × 274.68
or
f = 65.9232 N
Now,
work done by the boy, W₁ = 188.405 N × Displacement
= 188.405 N × 30
= 5652.15 J
and,
the
work done by the friction, W₂ = - 65.9232 N × Displacement
= - 65.9232 N × 30 m
= - 1977.696 J
[ since the friction force acts opposite to the direction of motion, therefore the workdone will be negative]
Answer:
it creates a gas called carbon dioxide. The gas begins to expand in the bottle and starts to inflate the balloon
Explanation:
Why does this happen? well, The faster-moving particles inside the bottle start to move faster and faster and soon they expand to fill the balloon.
The work done is by the centripetal force on mass m during an angular displacement of 2π revolutions mv²2π /r J
Centripetal force - a force acts on an moving object in circular path.
the centripetal force is given by
F= mv²/r (equation1)
Work done is given by
W = Fd (equation 2)
d = 2π
work is done by the centripetal force on mass m during an angular displacement of 2π revolutions is given by:
to calculate work done using equation 1 in 2 we get
W = mv² d/r
W = mv² × 2π /r J
The work done is by the centripetal force on mass m during an angular displacement of 2π revolutions mv²2π /r J
To know more about centripetal force :
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Answer:
306 m/s
Explanation:
Law of conservation of momentum
m1v1 + m2v2 = (m1+m2)vf
m1 is the bullet's mass so it is 0.1 kg
v1 is what we're trying to solve
m2 is the target's mass so it is 5.0 kg
v2 is the targets velocity, and since it was stationary, its velocity is zero
vf is the velocity after the target is struck by the bullet, so it is 6.0 m/s
plugging in, we get
(0.1 kg)(v1) + (5.0 kg)(0 m/s) = (0.1 kg + 5.0 kg)(6.0 m/s)
(0.1)(v1) + 0 = 30.6
(0.1)(v1) = 30.6
v1 = 306 m/s
It will be
E = mgh.
where h and g are constant thus
m can be written as 4/3πr^3*density
E = 4/3πr^3* density
E? = 4/3π(2R)^3* density
= 4/3π8r^3
thus the e will be 4/3π8r^3* density/4/3πr^3*density nd thus you get 8E ..
