1. Answer: A skydiver whose air resistance is equal to that of her weight.
A skydiver free falls under gravity but her rate of fall slows down due to drag -air resistance. when this air resistance becomes equal to her weight, the two get balanced and the body does not accelerate or decelerates.
2. Answer: Gravity
Contact forces are those which act when there is physical contact between two bodies. For example: normal force, tension and spring force.
Non-contact forces act between two bodies even when they are at a distance apart. For example: gravity, electric force, magnetic force etc.
3. Answer: The tendency of an object's motion to remain the same.
Inertia is a property of matter by virtue of which it tends to remain in its state of motion or rest. It does depend on mass of the object, more the mass, more is inertia. For example, cycle can be easily moved but we need real push hard for a car to move.
4. Answer: 254 N
The man pushes the box with 310 N force at an angle of 55 degrees to the horizontal.
we can write this in terms of horizontal (
)and vertical component (
).
Horizontal component: 
Vertical component: 
The vertical component would act towards the floor making the job more difficult to move the job.
Answer:
They are the only joints that can do 360 degrees and rotate with their own axis. But, because of its free-moving, it is prone to any dislocation compared to other movable joints.
Explanation:
<h2>
Heat released in this process is 3516.7 J</h2>
Explanation:
A calorimeter has a heat capacity of 1265 J/°C
Heat capacity of calorimeter = 1265 J/°C
A reaction causes the temperature of the calorimeter to change from 22.34°C to 25.12°C
Change in temperature = 25.12 - 22.34 = 2.78°C
Heat released = Heat capacity of calorimeter x Change in temperature
Heat released = 1265 x 2.78 = 3516.7 J
Heat released in this process is 3516.7 J
<u>Answer:</u>
<u>air mass</u>
<u>Explanation:</u>
Remember, the weather of a particular location is often a description of the atmospheric condition of that particular place.
Indeed, the definition of an air mass fits the reporter's description above. As the name implies, <u>a particular air mass would represent the temperature characteristics of a particular area that has a constant or the same temperature and air pressure.</u>