(a) 392 N/m
Hook's law states that:
(1)
where
F is the force exerted on the spring
k is the spring constant
is the stretching/compression of the spring
In this problem:
- The force exerted on the spring is equal to the weight of the block attached to the spring:
- The stretching of the spring is
Solving eq.(1) for k, we find the spring constant:
(b) 17.5 cm
If a block of m = 3.0 kg is attached to the spring, the new force applied is
And so, the stretch of the spring is
And since the initial lenght of the spring is
The final length will be
Answer:
it becomes a gas
Explanation:
the matter expands, turning into steam, a gas.
Answer:
electrons exist in specified energy levels
Explanation:
In its gold-foil scattering with alpha particles, Rutherford proved that the plum-pudding model of the atom theorised by Thomson was wrong.
From his experiment, Rutherford inferred that the atom actually consists of a very small nucleus, where all the positive charge is concentrated, and the rest of the atom is basically empty, with the electrons (negatively charged) orbiting around the nucleus at very large distance.
However, Rutherford did not specify anything about the orbits of the electrons. Later, Bohr predicted that the electrons actually orbit the nucleus in specific orbits, each orbit corresponding to a specific energy level. Bohr's model found confirmation in the observation of the emission spectrum lines: when an electron in one of the higher energy level jumps down into an orbit with lower energy, the atom emits a photon which has an energy exactly equal to the difference in energy between the two orbits (and this energy of the photon corresponds to a precise wavelength).
Using conservation of energy and momentum we get m1*v1=(m1+m2)*v2 so rearranging for v2 and plugging the given values in we get:
(200000kg*1.00m/s)/(21000kg)=.952m/s
Answer:
2.5 m/s²
Explanation:
Given,
Initial speed ( u ) = 10 m/s
Final speed ( v ) = 20 m/s
Time ( t ) = 4 seconds
To find : Acceleration ( a ) = ?
Formula : -
a = ( v - u ) / t
a = ( 20 - 10 ) / 4
= 10 / 4
= 5 / 2
a = 2.5 m/s²
Therefore,
The acceleration of the scooter is 2.5 m/s²
