Answer:
Power = 2.45Kw or 2450 Watts.
Explanation:
<u>Given the following data;</u>
Mass, m = 250kg
Height, h = 2m
Time, t = 2secs
We know that acceleration due to gravity, g is equal to 9.8m/s²
Power can be defined as the energy required to do work per unit time.
Mathematically, it is given by the formula;
But Energy = mgh
Substituting into the equation, we have

Power = 2450 Watts
To convert to kilowatt (Kw), we would divide by 1000
Power = 2450/1000
Power = 2.45Kw.
Therefore, the average power output of the weightlifter is 2.45 Kilowatts.
Answer:
Social psychologists utilize experimental techniques to study how people are influenced by groups. Health psychologists rely on experimentation and research to better understand the factors that contribute to wellness and disease.
Explanation:
Actually it's

and it says that the energy of an object (E) is equal to the mass (m) of the object multiplied with the squared speed of light (

). This theory says that mass can be turned into energy and energy can be turned into mass. This is one of Einstein's theory of relativity.
Initial speed of the car (u) = 15 m/s
Final speed of the car (v) = 0 m/s (Car comes to a complete stop after driver applies the brake)
Distance travelled by the car before it comes to halt (s) = 63 m
By using equation of motion, we get:

Acceleration of the car (a) = -1.78 m/s²
Magnitude of the car's acceleration (|a|) = 1.78 m/s²
the answer would be B. the back emf increases, and the current drawn from the socket increases
more current is needed to make the motor move, like when you try to self crank a motor and the back wires are touching its harder to crank. and the emf increases since more current is being drawn in, strengthening the emf or increasing the emf