Answer:
a) W = - 318.26 J, b) W = 0
, c) W = 318.275 J
, d) W = 318.275 J
, e) W = 0
Explanation:
The work is defined by
W = F .ds = F ds cos θ
Bold indicate vectors
We create a reference system where the x-axis is parallel to the ramp and the axis and perpendicular, in the attached we see a scheme of the forces
Let's use trigonometry to break down weight
sin θ = Wₓ / W
Wₓ = W sin 60
cos θ = Wy / W
Wy = W cos 60
X axis
How the body is going at constant speed
fr - Wₓ = 0
fr = mg sin 60
fr = 15 9.8 sin 60
fr = 127.31 N
Y Axis
N - Wy = 0
N = mg cos 60
N = 15 9.8 cos 60
N = 73.5 N
Let's calculate the different jobs
a) The work of the force of gravity is
W = mg L cos θ
Where the angles are between the weight and the displacement is
θ = 60 + 90 = 150
W = 15 9.8 2.50 cos 150
W = - 318.26 J
b) The work of the normal force
From Newton's equations
N = Wy = W cos 60
N = mg cos 60
W = N L cos 90
W = 0
c) The work of the friction force
W = fr L cos 0
W = 127.31 2.50
W = 318.275 J
d) as the body is going at constant speed the force of the tape is equal to the force of friction
W = F L cos 0
W = 127.31 2.50
W = 318.275 J
e) the net force
F ’= fr - Wx = 0
W = F ’L cos 0
W = 0
<h3>
Answer:</h3>
Input work
<h3>
Explanation:</h3>
Concept being tested: Efficiency of machines
Therefore we need to know what is the efficiency of a machine
- Efficiency of a machine is the ratio of work output of machine to the work input expressed as a percentage.
Efficiency = (Work output ÷ Work input) × 100%
- Therefore, if the work input is equal to the work output then the efficiency of the machine will be 100%.
- Most machines are not 100% efficient due to loss of energy in form of heat due to friction of the moving parts of the machine.
<span>When stars are moving away (red shift) the wavelength increases and thus the object looks more reddish (Because red color has longer wavelengths). As opposed to when the star is moving closer the wavelength contracts (blue shift) and the object appears slightly blue. So, the statement is False.</span>
the answer should be b) molecules because molecules are what creates a amino acid
The mass is rising with a constant speed.
=> So it has no vertical acceleration.
=> So there is no net vertical force acting on it.
=> So the sum of the vertical forces on it is zero.
There are two vertical forces acting on the mass.
=> the force of gravity, pulling it down
=> the tension in the cable, pulling it up.
The force of gravity acting on the mass (its weight) is (mass) x (gravity).
=> That's (120 kg) x (9.8 m/s²) downward.
=> That's 1,176 newtons downward.
If the vertical forces add up to zero, the other force ... the tension in the cable ... must be the same magnitude in the opposite direction.
=> The force of tension in the cable is <em>1,176 newtons upward</em>.