Answer:
A). A Lever and Wheel and Axle.
Explanation:
1. A wheel axle is most obvious, as the wheels are connected via a chain and axle with spokes. This helps keep the wheels moving forward with less effort than walking.
2. A Lever is used to help Balance you as you ride the bike. Without it, you would tip over, and lose all the momentum you had gained up until that point.
3. (I took the test on e2020)
Answer:
5m/s to the right
Explanation:
Momentum = mass * velocity
Momentum before = momentum after
m₁u₁+m₂u₂ = m₁v₁+m₂v₂
3000*10 + 1000*0 = 3000*v₁ + 1000*15
30000-15000=3000v₁
15000=3000v₁
v₁=5m/s to the right (to the right because answer is positive)
Answer:
The weight of the wheelbarrow and the road is 784 N and the force required to lift the wheelbarrow is 784 N.
Explanation:
Given that,
The total mass of the wheelbarrow and the road is 80 kg.
The weight of an object is given by :
W = mg
where
g is acceleration due to gravity
So,
W = 80 × 9.8
= 784 N
So, the force required to lift the wheelbarrow is equal to its weight i.e. 784 N.
Answer:
* most of the emission would be in the infrared part, the visible radiation would be very small.
*total intensity of the semition decreases that the intensity depends on the fourth power of the temperature
Explanation:
The radiation emitted by the Sun is approximately the radiation of a black body, if the Sun were to cool, the maximum emission wavelength changes
λ T = 2,898 10⁻³
λ = 2,898 10⁻³ / T
if the temperature decreases the maximum wavelength the greater values are moved, that is to say towards the infrared. Therefore the emission curve also moves, in this case most of the emission would be in the infrared part, the visible radiation would be very small.
Furthermore, the total intensity of the semition decreases that the intensity depends on the fourth power of the temperature according to Stefan's law
P = σ A eT⁴
1) 0.0011 rad/s
2) 7667 m/s
Explanation:
1)
The angular velocity of an object in circular motion is equal to the rate of change of its angular position. Mathematically:
where
is the angular displacement of the object
t is the time elapsed
is the angular velocity
In this problem, the Hubble telescope completes an entire orbit in 95 minutes. The angle covered in one entire orbit is
rad
And the time taken is
Therefore, the angular velocity of the telescope is
2)
For an object in circular motion, the relationship between angular velocity and linear velocity is given by the equation
where
v is the linear velocity
is the angular velocity
r is the radius of the circular orbit
In this problem:
is the angular velocity of the Hubble telescope
The telescope is at an altitude of
h = 600 km
over the Earth's surface, which has a radius of
R = 6370 km
So the actual radius of the Hubble's orbit is
Therefore, the linear velocity of the telescope is:
