A 20 kg mass is dropped from a tall rooftop and accelerates at 9.8 m/s2. What is the weight of the dropped object?

Jim halves the distance between himself and a sound source. What is the change of decibels of the sound he hears?

The theory that the Earth's crust and part of the upper mantle are broken into sections that move on a fluid layer of the mantle is called ... A. Continental Drift B. Wegener's Theory C. Sea Floor Spreading D. Plate Tectonics

Explain what it means if a wave has a frequency of 3 Hz.

There are infinite black and white dots on a plane. Prove that the distance between one black dot and one white dot is one unit.

two electrons are located in a region of space where the magnetic field is zero. Electron A is at rest; and electron B is moving westward with a constant velocity. A non zero magnetic field directed eastward is then applied to the region.

If a force does not act parallel to the resulting displacement, what is the effect on the work done by the force?

A stick is a connection of two same - diameter metal rod 5 cm, and a length of both stick is 0,6m. The thermal conductivity of the first rod 92 cal / s. m.°C, and the second stick 50 cal / s. m.°C.

you can produce a sound by plucking a string or by blowing in a pipe. how are these two ways different?

There are four springs stretched by the same mass. Spring A: 25 cm Spring B: 10 cm Spring C: 100 cm Spring D: 1 cm Which spring is the strongest? A B C D

Consider a rough asphalt roadway with 17 cm curbs and one 3.75 m lane in each direction and a 1.45 m shoulder on each side. The road has a longitudinal slope of 0.75% and is crowned in the center with a transverse slope of 2.25%.