Answer:84.672 joules.
Explanation:
1) Data:
m = 7.2 kg
h = 1.2 m
g = 9.8 m / s²
2) Physical principle
Using the law of mechanical energy conservation principle, you have that the kinetic energy of the dog, when it jumps, must be equal to the final gravitational potential energy.
3) Calculations:
The gravitational potential energy, PE, is equal to m × g × h
So, PE = m × g × h = 7.2 kg × 9.8 m/s² × 1.2 m = 84.672 joules.
And that is the kinetic energy that the dog needs.
Compounds are formed as a result of elements that are joined and held together by strong forces called chemical bonds.
The net force acting on the car is 65 N to the left
The net force acting on an object is simply defined as the resultant force acting on the object.
From the question given, we obtained the following data:
- Force applied to the right (Fᵣ) = 250 N
- Force applied to the left (Fₗ) = 315 N
- Net force (Fₙ) =?
The net force acting on the car can be obtained as follow:
Fₙ = Fₗ – Fᵣ
Fₙ = 315 – 250
<h3>Fₙ = 65 N to the left </h3>
Therefore, the net force acting on the car is 65 N to the left
Learn more on net force: brainly.com/question/19549734
Answer:
1.53 seconds
Explanation:
Applying,
T = 2usin∅/g................ Equation 1
Where, T = time of flight, u = initial velocity, ∅ = angle of projectile to the horizontal, g = acceleration due to gravity
From the question,
Given: u = 15 m/s, ∅ = 30°
Constant: g = 9.8 m/s²
Substitute these values in equation 1
T = 2(15)(sin30°)/9.8
T = 15/9.8
T = 1.53 seconds
Hence the time rate of flight is 1.53 seconds
Answer:
![63.4^{\circ}](https://tex.z-dn.net/?f=63.4%5E%7B%5Ccirc%7D)
Explanation:
When unpolarized light passes through the first polarizer, the intensity of the light is reduced by a factor 1/2, so
(1)
where I_0 is the intensity of the initial unpolarized light, while I_1 is the intensity of the polarized light coming out from the first filter. Light that comes out from the first polarizer is also polarized, in the same direction as the axis of the first polarizer.
When the (now polarized) light hits the second polarizer, whose axis of polarization is rotated by an angle
with respect to the first one, the intensity of the light coming out is
(2)
If we combine (1) and (2) together,
(3)
We want the final intensity to be 1/10 the initial intensity, so
![I_2 = \frac{1}{10}I_0](https://tex.z-dn.net/?f=I_2%20%3D%20%5Cfrac%7B1%7D%7B10%7DI_0)
So we can rewrite (3) as
![\frac{1}{10}I_0 = \frac{1}{2}I_0 cos^2 \theta](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B10%7DI_0%20%3D%20%20%5Cfrac%7B1%7D%7B2%7DI_0%20cos%5E2%20%5Ctheta)
From which we find
![cos^2 \theta = \frac{1}{5}](https://tex.z-dn.net/?f=cos%5E2%20%5Ctheta%20%3D%20%5Cfrac%7B1%7D%7B5%7D)
![cos \theta = \frac{1}{\sqrt{5}}](https://tex.z-dn.net/?f=cos%20%5Ctheta%20%3D%20%5Cfrac%7B1%7D%7B%5Csqrt%7B5%7D%7D)
![\theta=cos^{-1}(\frac{1}{\sqrt{5}})=63.4^{\circ}](https://tex.z-dn.net/?f=%5Ctheta%3Dcos%5E%7B-1%7D%28%5Cfrac%7B1%7D%7B%5Csqrt%7B5%7D%7D%29%3D63.4%5E%7B%5Ccirc%7D)