Answer:
Option C is the correct answer.
Explanation:
Considering vertical motion of ball:-
Initial velocity, u = 2 m/s
Acceleration , a = 9.81 m/s²
Displacement, s = 40 m
We have equation of motion s= ut + 0.5 at²
Substituting
s= ut + 0.5 at²
40 = 2 x t + 0.5 x 9.81 x t²
4.9t² + 2t - 40 = 0
t = 2.66 s or t = -3.06 s
So, time is 2.66 s.
Option C is the correct answer.
Answer:
The correct answer is
a) 1, 2, 3
Explanation:
In rolling down an inclined plane, the potential energy is Transferred to both linear and rotational kinetic energy thus
PE = KE or mgh = 1/2×m×v² + 1/2×I×ω²
The transformation equation fom potential to kinetic energy is =
m×g×h = 
= 
= 
=
Therefore the order is with increasing rotational kinetic energy hence
the first is the sphere 1 followed by the disc 2 then the hoop 3
the correct order is a, 1, 2, 3
Answer:
K = -½U
Explanation:
From Newton's law of gravitation, the formula for gravitational potential energy is;
U = -GMm/R
Where,
G is gravitational constant
M and m are the two masses exerting the forces
R is the distance between the two objects
Now, in the question, we are given that kinetic energy is;
K = GMm/2R
Re-rranging, we have;
K = ½(GMm/R)
Comparing the equation of kinetic energy to that of potential energy, we can derive that gravitational kinetic energy can be expressed in terms of potential energy as;
K = -½U
As a wave moves through a medium, particles are displaced and return to their normal position after the wave passes.
Explanation:
A wave is a traveling disturbance that carries energy from one location to another. All waves move in straight lines outward and away from the source of a disturbance. Like the radiating circular ripples, the waves of water carry energy away from where a rock was dropped into the pond.
Waves can move as a single pulse or as a continuous series of waves, carrying energy away from its source. A pulse is a single disturbance, wave, or ripple that moves outward from the point of disturbance. A train of waves are many waves emitted over and over again from a single source.
As waves travel through matter, they will temporarily displace the molecules or particles in matter up-and-down or side-to-side. Waves move the energy but they do not carry the matter with them longitudinally as they move through matter. Once the disturbance passes, the medium will return to its original state or position.
Therefore, as the waves move through a medium, particles are displaced and return to their normal position after the wave passes.
