Answer:
Power = 70 W
Explanation:
Given that,
Force, F = 70 N
Height, h = 5 m
Time, t = 5 s
We need to find the power of the object. We know that,
Power = work done/time
Put all the values,

So, the required power is 70 W.
Answer:
the answer is B.
Explanation:
The claim is correct because Student Y can apply a force that is greater in magnitude than the frictional forces that are exerted on the student-student-skateboard system
The area of the circle with radius r is
A = πr²
The rate of change of area with respect to time is

The rate of change of the radius is given as

Therefore

When r = 10 ft, obtain

Answer: - 40π ft²/s (or - 127.5 ft²/s)
If something is traveling at 20 m/s constant speed AND its direction isn't changing, then its velocity is constant. Another way to say that is: Its acceleration is zero. Zero acceleration means zero NET force acting on the object, or a group of BALANCED forces acting on it, also called EQUILIBRIUM. The required answer is: YES.
If a real projectile is launched, the force of gravity acts on it vertically downward. There's no upward force acting on it to balance gravity. Therefore, the forces on the projectile are NOT balanced, there IS a net vertical force on it, and it's NOT in equilibrium. Too bad.
Answer:
it is chemical reactivity (D)
Explanation:
it is because chemical properties are properties that can be measured and observed only when matter undergoes a change to become an entirely different kind of matter.Which they include Chemical reactivity,flammable,and the ability to rust.And Chemical reactivity is the ability of matter to react chemically with other substances.