involves removing the top layer of earth, mining the coal, and then replacing the earth back on the surface.

A 1250 kg car is stopped at a traffic light. A 3550 kg truck moving at 8.33 m/s hits the car from behind If bumpers lock, how fast will the two vehicles move?

A man stands on a cliff that 10m above the sea. He throws a stone vertically upwards with velocity 5ms^-1.

A submarine is attempting to detect an aircraft carrier transiting the Straits of Malacca. The aircraft carrier has a source level of 90 dB. The submarine's passive sonar has a directivity index of 20 dB and a detection threshold of 15 dB.

What type (s) of wave (s) transports visible light?

A ball is thrown vertically upward. What is its acceleration at maximum altitude? A) It increases C) It becomes zero D) It remains constant

A lorry with a mass of 5000kg accelerates to overtake a caravan on the motorway. Its acceleration is 1.5m/s². What force must the engine be providing? You can ignore the effects of friction and air resistance

Norma kicks a soccer ball with an initial velocity of 10.0 meters per second at an angle of 30.0% if the ball moves though the air for 3.2 seconds what's the horizontal distance traveled by the ball

Suppose s (t) is the position of an object moving along a line at time t is greater than or equal to 0. What is the average velocity between the times t=a and t=b? What is the instantaneous velocity at t=a?

Estimate how long it would take one person to mow a football field using an ordinary home lawn mower. suppose that the mower moves with a 1-km/h speed, has a 0.5-m width, and a field is 360 ft long and 160 ft wide. 1 m = 3.281 ft.

Badri makes the table below to review the factors that affect the electric force between objects. Which change will correct the error in Badri's table?