Answer:
2.04m/s²
Explanation:
Complete Question
<em>A stationary 10 kg object is located on a table near the surface of the earth. The coefficient of kinetic friction between the surfaces is 0.2. A horizontal force of 40 N is applied to the object. Find the acceleration of the object.</em>
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According to Newtons second law;
\sum F_x = ma_x
F_m - F_f = ma_x
Fm is the applied force
Ff is the frictional force
m is the mass
a is the acceleration
Substitute the given values
40N - nmg = 10a
40 - 0.2(10)(9.8) = 10a
40 - 19.6 = 10a
20.4 = 10a
a = 20.4/10
a = 2.04m/s²
<em>Hence the acceleration of the object is 2.04m/s²</em>
Answer:
a) W_total = 8240 J
, b) W₁ / W₂ = 1.1
Explanation:
In this exercise you are asked to calculate the work that is defined by
W = F. dy
As the container is rising and the force is vertical the scalar product is reduced to the algebraic product.
W = F dy = F Δy
let's apply this formula to our case
a) Let's use Newton's second law to calculate the force in the first y = 5 m
F - W = m a
W = mg
F = m (a + g)
F = 80 (1 + 9.8)
F = 864 N
The work of this force we will call it W1
We look for the force for the final 5 m, since the speed is constant the force must be equal to the weight (a = 0)
F₂ - W = 0
F₂ = W
F₂ = 80 9.8
F₂ = 784 N
The work of this fura we will call them W2
The total work is
W_total = W₁ + W₂
W_total = (F + F₂) y
W_total = (864 + 784) 5
W_total = 8240 J
b) To find the relationship between work with relate (W1) and work with constant speed (W2), let's use
W₁ / W₂ = F y / F₂ y
W₁ / W₂ = 864/784
W₁ / W₂ = 1.1
Answer:
<h3>The answer is 1.92 g/cm³</h3>
Explanation:
The density of a substance can be found by using the formula
From the question
mass = 2.5 g
Volume = 1.3 cm³
We have
We have the final answer as
<h3>1.92 g/cm³</h3>
Hope this helps you
Answer:
The mechanical energy of the satellite is about 12 Gigajoules
Explanation:
The total mechanical energy is the sum of the kinetic and potential energy:
While we can determine the potential energy from the given values (height above earth's surface), to calculate the kinetic energy the velocity of the satellite needs to be determined first.
The formula for orbital velocity is:
with G the gravitational constant, m_E the mass of the Earth, and r the satellite distance measured from the center of the Earth:
This velocity points in the direction of the tangent of the orbit.
Now the kinetic and total mechanical energy can be calculated:
The mechanical energy of the satellite is about 12 Gigajoules