Explanation:
in my opinion I'd say it's gravity because it's making the book stay in it's one and only position pulling the book at the center of the desk
Yes. Kinetic energy is a form of mechanical energy and friction will turn that kinetic energy into heat.
Answer:
Explanation:
still water speed is 50 m / 25.0 s = 2.00 m/s or 200 cm/s
In lane 1 the effective speed would be 201.2 cm/s
5000 cm / 201.2 cm/s = 24.85 s
The change is 25.00 - 24.85 = 0.15 s decrease in time
In lane 8, the effective speed would be 198.8 cm/s
5000 cm / 198.8 cm/s = 25.15 s
The change is 25.00 - 25.15 = 0.15 s increase in time
Answer:
The speed of the resistive force is 42.426 m/s
Explanation:
Given;
mass of skydiver, m = 75 kg
terminal velocity, 
The resistive force on the skydiver is known as drag force.
Drag force is directly proportional to square of terminal velocity.

Where;
k is a constant

When the new drag force is half of the original drag force;

Therefore, the speed of the resistive force is 42.426 m/s
Answer:

Explanation:
<u>Diagonal Launch
</u>
It's referred to as a situation where an object is thrown in free air forming an angle with the horizontal. The object then describes a known path called a parabola, where there are x and y components of the speed, displacement, and acceleration.
The object will eventually reach its maximum height (apex) and then it will return to the height from which it was launched. The equation for the height at any time t is


Where vo is the magnitude of the initial velocity,
is the angle, t is the time and g is the acceleration of gravity
The maximum height the object can reach can be computed as

There are two times where the value of y is
when t=0 (at launching time) and when it goes back to the same level. We need to find that time t by making 

Removing
and dividing by t (t different of zero)

Then we find the total flight as

We can easily note the total time (hang time) is twice the maximum (apex) time, so the required time is
