If Speed = Distance / Time, then a marble rolling 49 cm in 7 seconds is moving at
343 cm/s
.142 cm/s
7 cm/s
not moving at all.

How many times did thomas edison mess up the light bulb

Ascientific blank must be testable and capable of being proven false?

Chameleons catch insects with their tongues, which they can rapidly extend to great lengths. in a typical strike, the chameleon's tongue accelerates at a remarkable 220 m/s2 for 20 ms, then travels at constant speed for another 30 ms.