Answer:
Meter, Gram and Liter.
Explanation:
In the metric system, the standard units for the below are;
Length - Meter
Mass - Gram
Volume - Liter.
The first: alright, first: you draw the person in the elevator, then draw a red arrow, pointing downwards, beginning from his center of mass. This arrow is representing the gravitational force, Fg.
You can always calculate this right away, if you know his mass, by multiplying his weight in kg by the gravitational constant

let's do it for this case:

the unit of your fg will be in Newton [N]
so, first step solved, Fg is 637.65N
Fg is a field force by the way, and at the same time, the elevator is pushing up on him with 637.65N, so you draw another arrow pointing upwards, ending at the tip of the downwards arrow.
now let's calculate the force of the elevator

so you draw another arrow which is pointing downwards on him, because the elevator is accelating him upwards, making him heavier
the elevator force in this case is a contact force, because it only comes to existence while the two are touching, while Fg is the same everywhere
Answer:
Part a)

Part b)

Part c)
Speed is more than the required speed so it will reach the top
Explanation:
Part a)
As we know that there is no frictional force while block is moving on horizontal plane
so we can use energy conservation on the block



Part b)
If the track has average frictional force of 7 N then work done by friction while block slides up is given as



work done against gravity is given as



Now by work energy equation we have



Part c)
now minimum speed required at the top is such that the normal force must be zero



so here we got speed more than the required speed so it will reach the top
Answer:

Explanation:
We should first find the velocity and acceleration functions. The velocity function is the derivative of the position function with respect to time, and the acceleration function is the derivative of the velocity function with respect to time.

Similarly,

Now, the angle between velocity and acceleration vectors can be found.
The angle between any two vectors can be found by scalar product of them:

So,

At time t = 0, this equation becomes

Hey there!
No, that would be a biologist. Biologists study biology, or life. They're focused on life cycles, cells, evolution, and so much more.
Physicists focus on physics. They learn about forces, motion, and the study of the universal forces like gravity, momentum, and speed. Just like mathematics, they study patterns and look for new discoveries to be found in the fields of science, physics, and even mathematics.
Hope this helps!