Why do scientist use radioactive decay to figure out how old stuff is

A father lifts a toddler 1.5m up in the air. The child gains 187.5J of gravitational potential energy as a result. What is the mass of the toddler? (Assume that the gravitational field strength is 10N/kg.)

A balloon was partially filled with helium gas at room temperature. It occupied 4.0 liters of volume at 700.0 mm Hg atmospheric pressure. When the balloon was released, it traveled upward until it burst at 99 mm Hg atmospheric pressure.

Millikan's oil-drop experiment measures the charge on individual oil drops. Why would you try to set the electric field force on a drop equal to the gravitational force on that drop?

If Vector A is (3, 0) and Vector B is (-3, 3), what is the resultant?

What does power measure the rate of? A. force B. energy C. work D. distance

What property of sound enables us to distinguish one sound source from another?

The table below shows the right ascensions of two stars at a location. Star 1 - 4 right ascension (in Hour) Star 2 - 3 right ascension (in Hour) Which of these statements is correct about the stars?

H-2 + H-3 → He-4 + Consider the nuclear reaction that takes place in the sun. Two nuclides of hydrogen fuse to form helium. Is helium the only product of this reaction? If no, identify any additional products. A) Yes, He-4 is the only product. B) No.

Hat is a scientific theory? Make up your own scientific theory.

Which of the following is an example of a velocity? O A. 12 m/s O B. 45 km/hr south O C. 55 km/hr D. - 5 m/s2 east