Answer:
(a) W = 8.66 J
(b) Velocity = 2.40 m/s
Explanation:
(a) Work done is given as the product of force and displacement. That is:
W = F * d * cos(A)
Where F = force applied
d = distance moved
A = angle of ramp
Therefore, work done is:
W = 20 * 0.5 * cos30
W = 8.66 J
(b) Work done is equal to change in Kinetic energy. Since the initial kinetic energy is zero:
W = KE(final)
W = ½ * m * v²
Where v = final velocity
=> 8.66 = ½ * 3 * v²
v² = 5.773
v² = 2.40 m/s
Answer:
The mass of the second person is 28.91 kg
Explanation:
Given;
mass of the first adult, m₁ = 54.2 kg
distance of the first adult from the point of balance, x = 1.20 m
mass of the second adult, = m₂
distance of the second adult from the point of balance, y = 2.25 m
Taking moment about the point of balance, we will have
m₁x = m₂y
54.2 x 1.2 = 2.25y
2.25y = 65.04
y = 65.04/2.25
y = 28.91 kg
Therefore, the mass of the second person is 28.91 kg
A bathroom scales works due to gravity. Under normal
conditions, a reading can be obtained when your body is pushing some force on
the scale. However in this case, since you and the scale are both moving
downwards, so your body is no longer pushing on the scale. Therefore the answer
is:
<span>The reading will drop to 0 instantly</span>
Answer: D
Key thing to keep note, is "refraction"...
Look at some experiments on YouTube, it's helps me a lot.
