What causes digital pictures today to be clearer than digital pictures taken 20 years ago

Asmall grinding wheel has a moment of inertia of 4.0×10−5 kg⋅m2 . what net torque must be applied to the wheel for its angular acceleration to be 150 rad/s2 ?

What would be the radius of the earth if it had its actual mass but had the density of nuclei? express your answer to two significant figures and include the appropriate units.

Abus travels 280km south along a straight path with an average velocity of 88km/h to the south. the bus stops for 24 min, then it travels 210 km south with an average velocity of 75 km/h to the south. how long does the total trip last?