A480-kilogram horse runs across a field at a rate of 40 km/hr. what is the magnitude of the horse's momentum?
a) 12 km/hr
b) 19,200 km/hr
c) 19,200 kg x km/hr
d) 12 kg x km/hr
an object can only accelerate when the forces acting on it are unbalanced.
when that happens
-- the object's speed increases, or
-- its speed decreases, or
-- the direction of its motion changes.
the silvered walls
the silver coating on the inner bottle prevents heat transfer by radiation, and the vacuum between its double wall prevents heat moving by convection. the thinness of the glass walls stops heat entering or leaving the flask by conduction. the case surrounding the flask provides additional insulation.
thinking not sure but gammer rays are high energy and may cause damage to healthy cells