What is the difference between a rock that shows porphyry and a rock called tuff?

A box of books weighing 290 N is shoved across the floor of an apartment by a force of 400 N exerted downward at an angle of 34.9° below the horizontal. If the coefficient of kinetic friction between box and floor is 0.

If a star's parallax angle is too small to measure, what can you conclude about the star's distance from the Earth?

A force of 250 N is applied to a 1 kg softball when struck with a bat. what is the acceleration

When protons or neutrons are added to an atomic nucleus, energy is produced and this is called a reaction. A) fusion B) fission C) physical D) chemical

All electromagnetic waves travel at the same speed in a vacuum true or false

A small rock remains at rest in outer space while an astronaut pushes horizontally on it with a force of 20 N. Which of the following must be true? A. There is another horizontal force acting on the rock. B.

If an igneous rock has very large crystals of minerals that you can see when looking at it, which type of igneous rock is it

You have a 60-foot roll of fencing and a large field. You want to make two paddocks by continuing the fencing down the middle of a rectangular enclosure. What are the dimensions of the largest such enclosure you can make?

Crystallization is a separation technique used to produce rock candy from a sugar solution. true or false

A car traveling in a straight line has a velocity of 3.79 m/s at some instant. After 5.4 s, its velocity is 11.9 m/s. What is its average acceleration in this time interval? Answer in units of m/s 2