It is the very last answer
As we know that friction force on box is given by
here we know that
here we have
m = 12 kg
so now we have
now we will have
so it required minimum 49 N(approx) force to move the block
The runner has initial velocity vector
and acceleration vector
so that her velocity at time 
is
She runs directly east when the vertical component of 
is 0:
It's not clear what you're supposed to find at this particular time... possibly her position vector? In that case, assuming she starts at the origin, her position at time would be
so that after 10.4 s, her position would be
which is 19.9 m away from her starting position.
B is a correct answer. Positive attitudes can help us learn quicker. Hope it helped you, and have a great day.
-Charlie
Sediments are pieces of rock that come from other rocks that were eroded or broken by wind, water or other mechanical forces. Debris are pieces of other materials that were also swept away.
When these sediments and debris settle, they create layers. These layers are called beds. In time, several layers of other sediments and debris form on top of each other which press down onto the previous layers. Because of the pressure from the weight of the newer layers, the sediments and debris are pressed together and go through cementation. These then produce sedimentary rocks.
Metamorphic rocks form when rocks undergo heat and pressure. The heat comes from the friction resulting from the pressure. The heat can also come from radioactive decay. The rocks then slowly bake into new rocks called metamorphic rocks.
Igneous rocks form when magma and lava cool down. Magma is molten fluid found beneath the surface of the Earth. Lava is magma that has reached the surface of the Earth. When they cool down, they crystallize which make igneous rocks.
The difference between intrusive and extrusive igneous rocks is that one is made beneath the Earth and the other is made on the surface of the Earth. When magma cools, it takes a long time and the product of this cooling are intrusive igneous rocks. On the other hand, extrusive igneous rock is the result of lava cooling, which does not take as long to cool down because it occurs on the surface of the Earth.
Examples of the following types of rocks:
Sedimentary: limestone, sandstone, siltstone
Metamorphic: Marble, gneiss, slate
Igneous: Gabbro (intrusive), granite (Intrusive), obsidian (extrusive)
