Answer:
the work done by gravity on the boy is 604.62 J
Explanation:
Given;
distance the boy slides, d = 3 m
angle of inclination of the playground, θ = 40⁰
mass of the boy, m = 32 kg
The vertical height, h, above the ground through which the boy falls represents the height of the triangle which is the opposite side.
The distance through which the boy slides, d, represents the hypotenuse side of the right triangle.
The work done by gravity on the boy is calculated as;
W = P.E = mgh
= 32kg x 9.8m/s² x 1.928m
= 604.62 J
Therefore, the work done by gravity on the boy is 604.62 J
The lowest constant acceleration needed for takeoff from a 1.80 km runway is 2.8 m/s².
To find the answer, we need to know about the Newton's equation of motion.
<h3>What's the Newton's equation of motion to find the acceleration in term of initial velocity, final velocity and distance?</h3>
- The Newton's equation of motion that connects velocity, distance and acceleration is V² - U²= 2aS
- V= final velocity, U= initial velocity, S= distance and a= acceleration
<h3>What's the acceleration, if the initial velocity, final velocity and distance are 0 m/s, 360km/h and 1.8 km respectively?</h3>
- Here, S= 1.8 km or 1800 m, V= 360km/h or 100m/s , U= 0 m/s
- So, 100²-0= 2×a×1800
=> 10000= 3600a
=> a= 10000/3600 = 2.8 m/s²
Thus, we can conclude that the lowest constant acceleration needed for takeoff from a 1.80 km runway is 2.8 m/s².
Learn more about the Newton's equation of motion here:
brainly.com/question/8898885
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Use the conservation of angular momentum; angular momentum at the beginning = angular momentum at the end
Conservation of angular momentum:
I1 w1 = I2 w2
Where I is the moment of inertia. For a sphere, I=2/5 m R^2. Substituting into the equation above we get
w2 = I1 w1 / I2 = w1 m1 R1^2 / (m2 R2^2)
w2 = w1 4 * (R1/R2)^2
= 4*(1)*(7E5/7.5)^2
= 3.48E10 revs/(17days)
= 2.04705882 x 10^9 revs/sec
The reactants are on the left and the products are on the right of the equation
Answer:
The pencil is not pulled towards a person due to a very small magnitude of force between them, due to lighter masses.
Explanation:
Let us apply Newton's Law of Gravitation between a person and pencil.
Average Mass of a Normal Pencil = m₁ = 10 g = 0.01 kg
Average Mass of a Person = m₂ = 80 kg
Distance between both = r = 1 cm = 0.01 m (Taking minimal distance)
Gravitational Constant = G = 6.67 x 10⁻¹¹ N.m²/kg²
So,
F = Gm₁m₂/r²
F = (6.67 x 10⁻¹¹ N.m²/kg²)(0.01 kg)(80 kg)/(0.01 m)²
<u>F = 5.34 x 10⁻⁷ N</u>
This Force is very small in magnitude due to the light masses of both objects.
<u>Therefore, the pencil is not pulled towards a person due to a very small magnitude of force between them, due to lighter masses.</u>
