Avery powerful vacuum cleaner which has a hose of circular cross section can lift a brick of mass 12 kg when the hose is placed perpendicularly on a horizontal flat smooth face of a brick. what is the minimum radius the hose opening should have to achieve this?

a). 1.9 cm
b). 2.6
c). 1.4 cm
d). 3.2 cm

Aballet student who learns with the of his instructor is demonstrating learning.

Avoltaic cell converts chemical energy to

Abaseball is thrown from the outfield toward the catcher. when the ball reaches its highest point, which statement is true? (a)its velocity is not zero, but its acceleration is zero. (b) its velocity and its acceleration are both zero. (c) its velocity is perpendicular to its acceleration. (d) its acceleration depends on the angle at which the ball was thrown. (e) none of the above statements are true.