How do I find (With workings please) The change in time for the first quarter is seconds.
The change in time for the second quarter is seconds.
The change in time for the third quarter is seconds.
The change in time for the fourth quarter is seconds.

And the initial time and final time for the the first pic

Trumpeter a holds a b-flat note on the trumpet for a long time. person c is running towards the trumpeter at a constant velocity. person b is running away from the trumpeter at the same rate. person d is standing still the whole time. which person hears a frequency that is lower than the b-flat?

Anybody wanna ? (picture included? )

This is important. 1. which of the following is an si base unit for measuring length? (2 points) inch gram meter mole 2. which of the following units for distance is an si unit? (2 points) centimeter foot inch yard 3. which of the following tools should a scientist use to measure an object in meters? (2 points) electronic balance pan balance tape measure thermometer