Power is the rate work done given by dividing work done by unit time. It is measured in watts equivalent to J/s.
In this case the force by the student is mg = 490 N (taking g as 9.8m/s²)
Work done is given by force × distance,
Therefore, Power =(force × distance)/ time, but velocity/speed =distance/time
Thus, Power = force × speed/velocity
= 490 N × 1.25
= 612.5 J/S (Watts)
Hence, power will be 612.5 Watts.
Answer:
F=5833.3 N N
Explanation:
Newton's second law applied to the car
F= m*a Formula (1)
F: Force in Newtons (N)
m : mass in kg
a: acceleration ( m/s²)
kinematics car
vf= v₀ + a*t Formula (2)
vf : final velocity (m/s)
v₀ : final velocity (m/s)
a : acceleration ( m/s²)
t : time t
Equivalences
1 km= 1000m
1 h = 3600 s
Data
m= 1000kg
v₀ = 90 km/h = 90*1000/3600 m/s = 25 m/s
vf= 0
t= 6 s
Problem Development
We calculate the acceleration replacing the data in the formula (2) :
0 = 25 + a*6
a= -25/6 = -4.16 m/s² ( The negative sign indicates that the car is braking)
We calculate the force is required to stop the car replacing the data in the formula (1)
-F = 1400 kg*(-4.16 m/s²)
F=5833.3 N
Answer:
Carbon 12
Explanation:
I don't 100% know what to put here, but...
When you remove the nucleus from an oxygen atom, almost everything of the base oxygen is essentially stripped away. Since almost everything is made of carbon, and Carbon 12 is one of the most common forms of Carbon, Carbon 12 would be what is left.
Answer:
Fusion
Explanation:
The thermonuclear fusion(only occurs at extreme conditions of temperature and pressure like interiors of stars) of Hydrogen takes place in The Sun's core.
Every four hydrogen atoms combine to form a Helium atom with a release of 26.7Mev of energy.
On a large scale this amount of energy can be very huge.
It is calculated that tis proces has being going on for the past 
years and with the amount of Hydrogen left will be sufficient to keep it going for the same amount of time in the future.
After this process ends,the Sun's core which will be mostly Helium,will start to cool and collapse under its own gravity.
Mechanical energy is sum of kinetic energy and potential energy
