Answer:
P = 450 J
Explanation:
Given that,
Mass of a child, m = 18 kg
The vertical distance from the top to the bottom of the slide is 2.5 metres.
The Gravitational field strength = 10 N/kg
We need to find the decrease in gravitational potential energy of the child sliding from the top to the bottom of the slide.
The formula for the gravitational potential energy is given by :
P = mgh
Substituting all the values,
P = 18 kg × 10 m/s² × 2.5 m
P = 450 J
Hence, the decrease in gravitational potential energy is 450 J.
Answer:
b) vary with the frequency of the light
Explanation:
The phone electric effect can be expressed as
K.E=(hv -W•)
Where K.E is the Kinectic energy
W• = work function of the metal
ν =frequency of the radiation
h = Planck's constat
Then, we can see that K.E is proportional linearly to "v" in the equation above.
Therefore, When light is directed on a metal surface, the kinetic energies of the photoelectrons vary with the frequency of the light
Answer:
Explanation:
Newton’s Second Law of Motion says that acceleration (gaining speed) happens when a force acts on a mass (object). Riding your bicycle is a good example of this law of motion at work. Your bicycle is the mass.
Answer:
Part a)
Part b)
Part c)
Explanation:
Part a)
As we know that frequency = 1 MHz
speed of electromagnetic wave is same as speed of light
So the wavelength is given as
Part b)
As we know the relation between electric field and magnetic field
Part c)
Intensity of wave is given as
Pressure is defined as ratio of intensity and speed
Answer:
c. 981 watts
Explanation:
Given:
- horizontal speed of treadmill,
- weight carried,
- grade of the treadmill,
<u>Now the power can be given by:</u>
(where grade is the rise of the front edge per 100 m of the horizontal length)
