Answer:
What is kinetic friction?
Kinetic friction is defined as a force that acts between moving surfaces. A body moving on the surface experiences a force in the opposite direction of its movement.
What causes it?
When the mass is not moving, the object experiences static friction. The friction increases as the applied force increases until the block moves. After the block moves, it experiences kinetic friction, which is less than the maximum static friction.
What does it generate?
When surfaces in contact move relative to each other, the friction between the two surfaces converts kinetic energy into thermal energy (that is, it converts work to heat). This property can have dramatic consequences, as illustrated by the use of friction created by rubbing pieces of wood together to start a fire.
Answer:
Sound wave X amplitude is greater than 'A' and its frequency is lesser than
'f'
Explanation:
The pitch of a sound is dictated by the frequency of the sound wave, while the loudness is dictated by the amplitude.
A high pitch sound corresponds to a high frequency and a low pitch sound corresponds to a low frequency.
The larger the amplitude of the waves, the louder the sound and vice-versa.
From the question,
Sound wave W has amplitude ‘A' and frequency 'f' and
Sound wave X is louder and lower in pitch than sound wave W.
Since sound wave X is louder, this means its amplitude is greater than 'A'.
Also, since sound wave X is lower in pitch, this means its frequency is lesser than 'f'.
Answer:
d)2.13 C s⁻¹
Explanation:
Rate of flow of heat through walls
=
K = .33
A = 6 X .4 X .4 =0.96
T₂-T₁ = 30+40 = 70
d = 5 x 10⁻³
Put these data in the relation above
Rate of flow of heat
= 
= 4435.2 Js⁻¹
Specific heat of gas = 2.5 R = 20.785 J
Rise in temp = 
= 2.13 degree celsius.
Electric field lines of positive charges are always radially outwards
So here all field lines must have tendency to move out radially as well as two field lines never intersects with each other
So here field lines also do not intersects with each other
So overall the figure C is perfectly representing the field lines of two positive charges as these lines are not intersecting and also originating from two positive charges.
So answer must be
<u><em>FIGURE C</em></u>
Answer:
a. 28.27 m/s
b. 12.75 m/s
c. No
Explanation:
a.
The bottom
Ek = Ep
¹/₂ * m * v² = m * g * h₁
v = √ 2 * g * h₁ = √ 2 * 9.8 * 40.8 m
v = 28.27 m/s
b.
At the top
Ek = Ep
¹/₂ * m * v² = m * g * h₁
v = √ 2 * g * h₁ = √ 2 * 9.8 * (40.8 - 32.5) m
v = 12.75 m/s
c.
No in this case the axis is the same of the motion so, the angle doesn't affect the result
