Answer:
Absence of light causes shadow
Explanation:
The shadow is of the black colour because it is formed by the white light from the sun. Black is the opposite colour of white. In case you use different colour of light to cast a shadow you will get a shadow of opposite colour of light used to cast shadow.
Answer:
The dose is 6 mSV
Explanation:
The absorbed dose (in gray - Gy) is the amount of energy that ionizing radiation deposits per unit mass of tissue. That is,
Absorbed dose = Energy deposited / Mass
while Dose equivalent (DE) (in Seivert -Sv) is given by
DE = Absorbed dose × RBE (Relative biological effectiveness)
First, we will determine the Absorbed dose
From the question, Energy deposited = 30mJ and Mass = 50kg
From,
Absorbed dose = Energy deposited / Mass
Absorbed dose = 30mJ/50kg
Absorbed dose = 0.6 mGy
Now, for the Dose equivalent (DE)
DE = Absorbed dose × RBE
From the question, RBE = 10
Hence,
DE = 0.6mGy × 10
DE = 6 mSv
Answer:
the weight of the object decreases when it is taken from the Earth to the Moon
Explanation:
The weight of an object is defined as the product of the mass of the object with the acceleration due to gravity of the Planet.
where,
W = weight of the object
m = mass of the object
g = acceleration due to gravity on the planet
The mass of an object remains constant everywhere in the universe. Therefore, the weight is directly proportional to the value of acceleration due to gravity.
The value of acceleration due to gravity on the Moon is lesser than its value on the Earth.
<u>Hence, the weight of the object decreases when it is taken from the Earth to the Moon </u>
Answer:
11. 5 N to the left.
12. 10 N to the right.
Explanation:
11. Determination of the net force.
Force in the left direction (Fₗ) = 10 N
Force in the right direction (Fᵣ) = 5 N
Net force (Fₙ) =?
The net force can be obtained as follow:
Fₙ = Fₗ – Fᵣ (Since the forces act in opposite direction)
Fₙ = 10 – 5
Fₙ = 5 N to left
Thus, the net force is 5 N to the left.
12. Determination of the net force.
Force in the right direction 1 (Fᵣ₁) = 5 N
Force in the right direction 2 (Fᵣ₂) = 5 N
Net force (Fₙ) =?
The net force can be obtained as follow:
Fₙ = Fᵣ₁ + Fᵣ₂ (Since the forces act in the same direction)
Fₙ = 5 + 5
Fₙ = 10 N to the right
Thus, the net force is 10 N to the right.
