What is the purpose of repeating a measurement using a different method?

What occurrence defines the end of the protostar phase of a star's life and the start of the main-sequence phase?

A car moving at a speed of 8.0 meters per second enters a highway and accelerates at 3.0 meters per second^2. How fast will the car be moving after it has accelerated for 56 meters?

While performing an experiment to establish relationship between weight of a rectangular wooden block lying on a horizontal table and the minimum force required to just move it using a spring balance, a student calculated the minimum force required

A car accelerates from 3.5 m/s to 17 m/s in 4.5 seconds. Find the acceleration of the car in m/s2

Which of the following will cause a current through an electrical circuit to decrease there can be more then one answer ... A. Decrease the voltage B. Decrease the resistance. C. Increase the voltage. D. Increase the resistance

Whats an example of projectile motion

The fact that the sun rises and sets at different times during the day depending on the time of year is an example of a data trend. True or False

What sample of matter is a single substance

What is a hydraulic machine and what is its purpose? Explain how a simple hydraulic machine performs work.

Is the muzzle velocity a scalar or vector quantity?