Answer:
a) The specific heat capacity means the amount of heat needed by a unit mass of a material to increase its temperature in one unit.
b) Liquid P - 
, Liquid Q - 
, Liquid R - 
, Liquid S - 
Explanation:
a) The specific heat capacity means the amount of heat needed by a unit mass of a material to increase its temperature in one unit.
b) Let suppose that heat transfer rates between liquids and surroundings are stable. The quantity of the heat released is determined by the following expression:
(1)
Where:
- Mass of the liquid, in kilograms.
- Specific heat capacity, in joules per kilogram-degree Celsius.
- Initial temperature of the sample, in degrees Celsius.
- Freezing point, in degrees Celsius.
Liquid P (
, 
, 
, 
)
Liquid Q (, 
, , 
)
Liquid R (, 
, , 
)
Liquid S (, 
, , 
)
Answer: 9 m
Explanation:
Work is said to be done when an unbalanced force causes displacement of the body.
Force is the product of mass (m) and acceleration (a).
Work = Force × Displacement
⇒W = F.s = ma.s
It is given that mass of the dresser is, m = 250 kg
work done, W = 126 J
Force acting on the dresser, F = 14 N
we need to find displacement, s
⇒126 J = 14 N × s
⇒ s = 126 J/ 14 N = 9 m
Hence, Laurie is able to move the dresser to about 9 m.
Answer:
Explanation:
Moment of inertia of the metal rod pivoted in the middle
= M l² / 12
If the spring is compressed by small distance x twisting the rod by angle θ
restoring force by spring
= k x
moment of torque about axis
= k x l /2
= k θ( l /2 )² ( x / .5 l = θ )
=
moment of torque = moment of inertia of rod x angular acceleration
k θ( l /2 )² = M l² / 12 d²θ/dt²
d²θ/dt² = 3 k/M θ
acceleration = ω² θ
ω² = 3 k/M
ω = √ 3 k / M
Out of the choices given, igniting the gas-air mixture supplies the heat for the hot reservoir in a car's engine. The correct answer is C.
