2-Pema runs to the school which is at a distance of 500m. He takes 25 seconds to reach the school.
What is the speed of pema with which he runs? [2 m]

Under the action of a constant force an object accelerates at 7.8 m/s2. what will the acceleration be if (a) the force is halved? (b) the object's mass is halved? (c) the force and the object's mass are both halved? (d) the force is halved and the object's mass is doubled?

If a rock weighing 54 n is submerged in a liquid with a density exactly twice that of water, what will be its new apparent weight reading in the liquid?

1,990,000,000,000,000,000,000,000,000,000 in scientific notation