When the system is experiencing a uniformly accelerated motion, there are a set of equations to work from. In this case, work is energy which consist solely of kinetic energy. That is, 1/2*m*v2. First, let's find the final velocity.
a = (vf - v0)/t
2.6 = (vf - 0)/4
vf = 10.4 m/s
Then W = 1/2*(2100 kg)*(10.4 m/s)2
W = 113568 J = 113.57 kJ
Answer: For number 9, the children would not be able to close the box.
Explanation: The combined force of the children is 55 N. The box spring overpowers them with 60 N. I hope this helps!
Answer:
<h2>35</h2>
Explanation:
According to snell's law which states that the ratio of the sin of incidence (i) to the angle of refraction(n) is a constant for a given pair of media.
sini/sinr = n
n is the constant = refractive index
Since the diver shines light up to the surface of a flat glass-bottomed boat, the refractive index n = nw/ng
nw is the refractive index of water and ng is that of glass
sini/sinr = nw/ng
given i = 30°, nw = 1.33, ng = 1.5, r = angle the light leave the glass
On substitution;
sin 30/sinr = 1.33/1.5
1.5sin30 = 1.33sinr
sinr = 1.5sin30/1.33
sinr = 0.75/1.33
sinr = 0.5639
r = arcsin0.5639
r ≈35°
angle the light leave the glass is 35°
Answer:
The average velocity is 7.5 km/h
Explanation:
Let's convert minutes to hours so our answer can be given in a common units of km/hour:
12 minutes = 12/60 hours = 0.2 hours
Now we estimate the average velocity calculating the distance travelled over the time it took:
1.5 / 0.2 km/h = 7.5 km/h
Answer:
The lenses with different focal length are four.
Explanation:
Given that,
Radius of curvature R₁= 4
Radius of curvature R₂ = 8
We know ,
Refractive index of glass = 1.6
When, R₁= 4, R₂ = 8
We need to calculate the focal length of the lens
Using formula of focal length
Put the value into the formula
When , R₁= -4, R₂ = 8
Put the value into the formula
When , R₁= 4, R₂ = -8
Put the value into the formula
When , R₁= -4, R₂ = -8
Put the value into the formula
Hence, The lenses with different focal length are four.
