A balloon is at a height of 81m and is ascending upwards with a velocity of 12m/s. A body of 2kg weight is dropped from it. If g=10m/s2, the body will reach the surface of the earth in how much time?

Gamma-ray bursters emit pulses of gamma rays with high energies. The frequency of the most energetic pulses has been measured at around 3.0 x 1021 Hz. What is the wavelength of these gamma rays?

what happens to the gravitational force when the distance between them stays the same and the mass of both objects is doubled

Streak is a reliable identifier of a mineral. true or false

In a single-slit diffraction experiment, the width of the slit through which light passes is increased. What happens to the width of the central bright fringe?

Technician A says that one heater hose should be hot and the other hose cool if the heater is functioning okay. Technician B says that both hoses should be hot to the touch.

Units for frequency?

True or false. there would be no like in earth without the sun

An electric force exists between which pair of objects? Check all that apply. a neutral object and a negative object two negative objects a neutral object and a positive object two positive objects a negative object and a positive object two neutral

What causes the acceleration to increase or decrease?

a glass rod obtains a positive chartge from being rubbed by silk. Is this due to the glass gaining protons, or losing electrons?