2.1) (i) W = mg downwards
(ii) N = R = Normal Reaction from the ground upwards
(iii) Fe = Force of engine towards the right
(iv) f = friction towards the left
(v) ma = Constant acceleration towards right.
2.2.1)
v = 25 m/s
u = 0 m/s
∆v = v - u = (25 - 0) m/s = 25 m/s
x = X
∆t = 50 s
a = 0.5 m/s².
2.2.2)
F = ma = 900 kg × 0.5 m/s² = 450 N.
2.2.3)
2.3)
Fe = f + ma
Fe - f = ma
For velocity to be constant,
a should be 0, or, a = 0,
Fe = f = 270 N
2.4.1)
v = 0
u = 25 m/s
a = -0.5 m/s²
v = u + at
t = -u/a = -(25)/(-0.5) = 50 s.
2.4.2)
x = -625/(2×(-0.5)) = 625 m.
Answer:
D. The temperature does not change during a phase change because the average kinetic energy does not change. Therefore, the potential energy in the bonds between molecules must change.
Explanation:
When there is a change of state (for example, from solid into a liquid, as in this example), when energy is added to the system, the temperature of the substance does not change.
The reason for this is that the energy supplied is no longer used to increase the average kinetic energy of the particle, but instead it is used to break the bonds between the different particles/molecules. For instance, since in this case the substance is changing from solid to liquid, all the energy supplied during the phase change is used to break the bonds between the molecules of the solid: when the process is done, all the molecules will be free to slide past each other, and the substance has turned completely into a liquid.
The bonds between molecules store potential energy: therefore, this means that the energy supplied during the phase change is not used to change the kinetic energy, but to change the potential energy in the bonds between the molecules.
As we know that acceleration is directly proportional to force, therefore as the force is doubled, acceleration gets doubled too.
Answer:
t = 1.58 s
Explanation:
given,
Speed of ranger, v = 56 km/h
v = 56 x 0.278 = 15.57 m/s
distance, d = 65 m
deceleration,a = 3 m/s²
reaction time = ?
using stopping distance formula
t is the reaction time
t = 1.58 s
hence, the reaction time of the ranger is equal to 1.58 s.
The tension in the two chains T1 and T2 is 676.65 N and 542.53 N respectively.
<h3>Principle of moments</h3>
The Principle of Moments states that when a body is in equip, the sum of clockwise moment about a point is equal to the sum of anticlockwise moment about the same point.
The formula for calculating moment is given below:
- Moment = Force × perpendicular distance from the pivot
<h3>Calculating the tension in the chains</h3>
From the principle of moments:
Let tension in chain 1 be T1 and tension in chain 2 be T2.
T1 + T2 = 150 + 650 + 419
T1 + T2 =1219
Taking all distances from chain 1,
Sum of Moments = 0
419 × 0.5 + 150 × 0.85 + 650 × 0.9 = T2 × 1.7
T2 = 922/17
T2 = 542.35 N
Then, T1 = 1219 - 542.35
T1 = 676.65 N
Therefore, the tension in the two chains T1 and T2 is 676.65 N and 542.53 N respectively.
Learn more about tension and moments at: brainly.com/question/187404
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