Answer:
A star uses fusion as an energy source by building larger atoms from smaller atoms.
Explanation:
Nuclear fission and fusion are two processes at which an atomic nucleus is changed to produce energy. Fission is the process splitting heavy atomic into lighter atomic nuclei.
So, fusion is the combination of smaller atoms to form larger atoms and star uses this as source of energy.
Fusion is the process at which light atomic nuclei are merged or fused together to form heavier nuclei.
The energy source for all stars is nuclear fusion. In a nuclear fusion reaction, the nuclei of two atoms combine to create a new atom. Most commonly, in the core of a star, two hydrogen atoms fuse to become a helium atom.
Answer:
C
Explanation:
- Let acceleration due to gravity @ massive planet be a = 30 m/s^2
- Let acceleration due to gravity @ earth be g = 30 m/s^2
Solution:
- The average time taken for the ball to cover a distance h from chin to ground with acceleration a on massive planet is:
t = v / a
t = v / 30
- The average time taken for the ball to cover a distance h from chin to ground with acceleration g on earth is:
t = v / g
t = v / 9.81
- Hence, we can see the average time taken by the ball on massive planet is less than that on earth to reach back to its initial position. Hence, option C
Answer:
The specific kinetic energy of a mass is 0.8 kJ/kg
Explanation:
Given that,
Velocity = 40 m/s
Specific kinetic energy is the kinetic energy per unit mass.
We need to calculate the specific kinetic energy
Using formula of specific kinetic energy
Put the value into the formula
We know that,
1 kJ = 1000 J
or, 1J=0.001 KJ
The specific energy is
Hence, The specific kinetic energy of a mass is 0.8 kJ/kg
Answer:
0 N, 3.49 m/s
Explanation:
Draw a free body diagram for the bucket at the top of the swing. There are two forces acting on the bucket: weight and tension, both downwards.
If we take the sum of the forces in the radial direction, where towards the center is positive:
∑F = ma
W + T = m v² / r
The higher the velocity that Rony swings the bucket, the more tension there will be. The slowest he can swing it is when the tension is 0.
W = m v² / r
mg = m v² / r
g = v² / r
v = √(gr)
Given that r = 1.24 m:
v = √(9.8 m/s² × 1.24 m)
v = 3.49 m/s
