Answer:
c
Explanation:
because it is made out of metel
Answer:
Explanation:
specific heat of marble is 880 J/kg °C
specific heat of brass is 920 J/kg °C
If Q heat is given to a body of mass m and specific heat s , and there is a rise of temperature t
Q = m s t
t = Q / m s
if Q and m is constant
t is inversely proportional to specific heat .
so rise in temperature will be inversely proportional to specific heat .
lower the specific heat , higher will be the rise in temperature . Since marble has lower specific heat , rise in temperature in marble will be higher and quicker .
So brass will take longer time to warm up.
Answer:
Required mass of sand is 20 kg
Explanation:
Given:
Mass of the plank = 25 kg
Distance of the Center of gravity of the Plank from the fulcrum = 
Distance of the Center of gravity of the sand box from the fulcrum =
Balancing the torque due to the plank and the sand box with respect to the fulcrum
Torque = Force × perpendicular distance
thus, we get
(25 × g) × 0.5 = weight of sand × 0.625
where, g is the acceleration due to gravity
or
(25 × g) × 0.5 = (mass of sand × g) × 0.625
or
mass of sand = 20 kg
<u>Hence, the required mass of the sand is </u><u>20 kg</u>