Explanation:
Work cannot be increased by using a machine of some kind.
Answer:
A kilowatt (kW) is a unit of power.
Explanation:
The power of an object is given by :

Here,
E is the energy required
t is time
The SI unit of power is Watts and the SI unit of energy is Joule. the commercial unit of energy is kilowatt per hour.
Option (1) : A kilojoule (kJ) is a unit of power is incorrect.
Option (2) : A gigawatt (GW) is a unit of energy is incorrect.
Option (3) : A watt (W) is a unit of energy is incorrect.
Option (4) : A kilowatt x hour per year (kWh/yr) is a unit of energy is incorrect.
Option (4) : A kilowatt (kW) is a unit of power is correct.
Hence, the correct option is (d).
Answer:
E. Zero Maximum
Explanation:
At the point of maximum displacement, the speed is zero while the restoring force is maximum. In fact:
- The restoring force is given by
, where k is the spring constant and x is the displacement - at the point of maximum displacement, x is maximum, so F is maximum as well
- the total energy of the system is sum of kinetic energy and elastic potential energy:

where m is the mass of the system and v is the speed. Since E (the total energy) is constant due to the law of conservation of energy, we have that when K increases, U decreases, and viceversa. As a result, when x increases, v decreases, and viceversa. At the point of maximum displacement, x is maximum, so v will have its minimum value (which is zero, since the system is changing direction of motion).
Answer:
<em>Well, Your answer will be is </em><em>840.96 mi. </em>
<em>Good Luck!</em>

- Let, the maximum height covered by projectile be


- Projectile is thrown with a velocity = v
- Angle of projection = θ
- Velocity of projectile at a height half of the maximum height covered be

______________________________
Then –










- Now, the vertical component of velocity of projectile at the height half of
will be –


Therefore, the vertical component of velocity of projectile at this height will be–
☀️
