Answer:
(B) The balls reach the ground at the same instant.
Explanation:
Since it is a projectile motion, the time required to reach the ground is given by
t = √2h/g
Where h is the height from which the balls are thrown and g is the acceleration due to gravity.
Since both of the balls were thrown from the same height and the acceleration of both balls are also same they will reach the ground at the same instant.
Answer:
C
Explanation:
To solve this question, we will need to develop an expression that relates the diameter 'd', at temperature T equals the original diameter d₀ (at 0 degrees) plus the change in diameter from the temperature increase ( ΔT = T):
d = d₀ + d₀αT
for the sphere, we were given
D₀ = 4.000 cm
α = 1.1 x 10⁻⁵/degrees celsius
we have D = 4 + (4x(1.1 x 10⁻⁵)T = 4 + (4.4x10⁻⁵)T EQN 1
Similarly for the Aluminium ring we have
we were given
d₀ = 3.994 cm
α = 2.4 x 10⁻⁵/degrees celsius
we have d = 3.994 + (3.994x(2.4 x 10⁻⁵)T = 3.994 + (9.58x10⁻⁵)T EQN 2
Since @ the temperature T at which the sphere fall through the ring, d=D
Eqn 1 = Eqn 2
4 + (4.4x10⁻⁵)T =3.994 + (9.58x10⁻⁵)T, collect like terms
0.006=5.18x10⁻⁵T
T=115.7K
Answer:
e) half
Explanation:
as we know relation b/w charge(Q) , capacitance (C) and voltage (V) is
Q = CV ...........(i)
we also know capacitance of a capacitor for separation d and area A is
C = ∈₀A/d ...........(ii)
from the above equation it is clear that C is inversely proportional to separation if separation doubled capacitance will reduced to half and from equation first charge is directly proportional to capacitance.
that s why magnitude of charge will reduced to half
so option (e) is right answer
Answer:
B) momentum and mechanical energy
Explanation:
In classical physics, a closed system is a system that does not exchange any matter with the surrounding, and on which there are no external forces acting on it.
Due to this definition, we have the following consequences:
- In a collision in a closed system, momentum is always conserved. This is because there is exchange of matter with the surroundings (so, no mass can be lost), and also because there are no external forces acting on the objects inside the system. In fact, the variation of the total momentum of the system is related to the net force acting on the system:
but since the net force F is zero, then the variation of momentum, , is also zero, therefore the momentum is constant.
- Also, mechanical energy is conserved. Mechanical energy is the sum of potential energy and kinetic energy of the system: again, since there are no external forces acting on the system, energy cannot be dissipated, so the total energy of the system cannot change.