A man dressed in all black is walking down a country lane. Suddenly, a large black car with no lights on comes around the corner and screeches to a halt. How did the car's driver know he was there?

this is tricky

Deep currents circulate seawater around the globe due to differences in the density of water at different locations. Two factors that can alter the density of water are salinitymarine lifespecific heat and windtemperatureEarth's rotation.

A bug makes 30 jumps on the surface of the water each minute. What is the frequency of the waves he produces (in Hertz) ?

Why are machines not a 100% efficient?

Why do we use a spaceship in outer space, far from other objects, to illustrate the principle that an object that does not interact with anything travels at constant speed in a straight line (Newton's first law) ? Why not a car or a train?

A total charge of 4.70 is distributed on two metal spheres. When the spheres are 10 cm apart, they each feel a repulsive force of 4.7 x 10^11 N. How much charge is on the sphere and which has the lower amount of charge?

An object floats in liquid of density 1.2*10kgm/3 with one quarter of its volume above the liquid surface. Determine the density of the object

In cloud formation, water vapor turns into water droplets which get bigger and bigger until it rains. This will cause the temperature of the air in the clouds to: a. get warmer. b. get cooler. c.

Find the work done by a 25N force applied for 6 meters

The buildup of charges on an object is called

Which of the following statements is true? The freezing and boiling temperatures of a substance are the same. The freezing and condensation temperatures of a substance are the same. The freezing and melting temperatures of a substance are the same.