20 Distinguish between real and apparent cubic
expansivities of a liquid.
A glass bottle full of mercury has mass 500 g.
On being heated through 35°C, 2.43 g of
mercury are expelled. Calculate the mass o
mercury remaining in the bottle (cubic
expansivity of mercury is 1.8 x 10-4 per k,
linear expansivity of glass is
8.0 x 10-6 per k

Amachinist turns the power on to a grinding wheel, at rest, at time t = 0 s. the wheel accelerates uniformly for 10 s and reaches the operating angular velocity of 96 rad/s. the wheel is run at that angular velocity for 40 s and then power is shut off. the wheel slows down uniformly at 1.5 rad/s2 until the wheel stops. in this situation, the time interval of deceleration is closest to:

The force it would take to accelerate an 900-kg car at the rate of 6m/s2

Four point charges each having charge q are located at the corners of a square having sides of length a. find symbolic expressions for the following. (a) the total electric potential at the center of the square due to the four charges (use any variable or symbol stated above along with the following as necessary: ke.) vtotal= (b) the work required to bring a fifth charge p from infinity to the center of the square (use any variable or symbol stated above along with the following as necessary: w=