Answer:112.82 m/s
Explanation:
Given
range of arrow=68 m

as the arrow travels it acquire a vertical velocity 

-------1
Range is given by
R=ut
where u=initial velocity


substitute the value of t in eqn 1

--------2
and 

substitute it in 2


u=112.82 m/s
Answer:
533.33 nm
Explanation:
Since dsinθ = mλ for each slit, where m = order of slit and λ = wavelength of light. Let m' = 10 th order fringe of the first slit of wavelength of light, λ = 640 nm and m"= 12 th order fringe of the second slight of wavelength of light, λ'.
Since the fringes coincide,
m'λ = m"λ'
λ' = m'λ/m"
= 10 × 640 nm/12
= 6400 nm/12
= 533.33 nm
Answer:
4.14 eV
Explanation:
f = 1.0 ×10^15 Hz
h= 6.63×10^-34 J s ( this is called PLANCK 'S CONSTANT)
ENEGY = E = ?
E = hf ( THIS IS FORMULA FOR ENERGY OF ONE QUANTA OR ONE PHOTON )
E= 6.63×10^-34×1.0 ×10^15
E = 6.63×10^-19 J
As 1eV = 1.6×10^-19 J so changing energy in eV from joules we will divide energy by 1.6×10^-19
hence E in eV = 6.63×10^-19/(1.6×10^-19)
E = 4.14 eV
Answer: "B" Changing Position
Great Question!
Explanation: <u><em>When a ball bounces to the ground it hits the ground with some energy. The amount of energy with which it hits the ground is kinetic energy. When it comes in the contact with the ground kinetic energy gets converted into potential energy. This potential energy again gets converted into kinetic energy and balls moves again from the ground and bounces multiple times. So, the ball ends up changing position</em></u>
<u><em /></u>
Answer:
0.853 m/s
Explanation:
Total energy stored in the spring = Total kinetic energy of the masses.
1/2ke² = 1/2m'v².................... Equation 1
Where k = spring constant of the spring, e = extension, m' = total mass, v = speed of the masses.
make v the subject of the equation,
v = e[√(k/m')].................... Equation 2
Given: e = 39 cm = 0.39 m, m' = 0.4+0.4 = 0.8 kg, k = 1.75 N/cm = 175 N/m.
Substitute into equation 2
v = 0.39[√(1.75/0.8)
v = 0.39[2.1875]
v = 0.853 m/s
Hence the speed of each mass = 0.853 m/s