Which elements are found in a high proportion in Earth's crust?

aluminum and iron

oxygen and silicon

calcium and sodium

potassium and magnesium

What causes clouds of dust and gas to form a protostar

6-A man standing in a valley between two parallel mountains fires a gun and hears echo at an interval of 2. 3.5s. What is (a) the distance between two mountains () the location of the man with respect to the mountain. (speed of sound=334 m/s)

An uncharged metal sphere hangs from a nylon thread. When a positively charged glass rod is brought close to the metalsphere, the sphere is drawntoward the rod. But if the sphere touches the rod, it suddenly flies away from the rod.

The position of a ball rolling in a straight line is given by x=2-3.6t+4.4t2, where x is in meters and t in seconds.

HNO3 (aq) + H20 (1) ► NO3 - (aq) + H30 + (aq) es Which substance in the reaction is considered to be the acid? HNO3 H2O NO3 H30

If a car rolls gently off a vertical cliff, how long does it take to reach 90km/hr.

In the game of volleyball, what skill relates to Newton's second law

The minimum breaking distance d in feet for a typical vehicle can be modeled with the equation d (v) = 0.045v2, where v is the vehicle's speed in miles per hour.

A 2kg blob of putty moving at 4 m/s slams into a 6kg blob of putty at rest what is the speed of the to stick together blobs immediately after colliding

A stone is thrown vertically upward with a speed of 12m/s from the edge of a cliff 70 m high (a) How much later it reaches the bottom of the cliff? (b) What is its speed just before hitting? And (c) what total distance did it travel? (Ans: 5.