Answer:
At an angle of 
Explanation:
Assume the river flows from East to West so for the swimmer to cross across it, assume he crosses it from West to East.
The resultant speed will be given by
Answer:
17 °C
Explanation:
From specific Heat capacity.
Q = cm(t₂-t₁)................. Equation 1
Where Q = Heat absorb by the metal block, c = specific heat capacity of the metal block, m = mass of the metal block, t₂ = final temperature, t₁ = Initial temperature.
make t₁ the subject of the equation
t₁ = t₂-(Q/cm)............... Equation 2
Given: t₂ = 22 °C, Q = 5000 J, m = 4 kg, c = 250 J/kg.°c
Substitute into equation 2
t₁ = 22-[5000/(4×250)
t₁ = 22-(5000/1000)
t₁ = 22-5
t₁ = 17 °C
Given data:
* The mass of the ball is 2 kg.
* The gravitational field strength at the surface of planet X is 5 N/kg.
Solution:
The weight of the ball on the planet X is,
where m is the mass of ball, a is the gravitational field strength,
Substituting the known values,
Thus, the weight of the ball on the surface of planet X is 10 N.
Answer:
False
Explanation:
All the lanthanides are not radioactive in nature. Just one of the lanthanides are radioactive.
- The lanthanides belong to the f-block on the periodic table
- Only Promethium in this group are radioactive in nature.
- Other elements in the lanthanide series might have radioactive isotopes.
