Answer:
24 m/s²
Explanation:
The given parameters are;
The initial acceleration of the object, a = 16 m/s²
Let 'm' represent the initial mass of the object
The initial force acting on the object, F = m × a
∴ F = 16 × m = 16·m
When the mass is doubled, we have;
The new mass of the object, m₂ = 2 × m = 2·m
When the net force acting on the object triples, we have;
The new net force acting on the object, F₂ = 3 × F = 3 × 16·m = 48·m
From F = m × a, we have;
a = F/m
∴ The new acceleration of the object, a₂ = F₂/m₂
From which, by plugging in the values, we have;
a₂ = 48·m/(2·m) = 24
The new acceleration of the object, a₂ = 24 m/s².
Answer:
The increase in temperature of the bullet is 351.1 kelvin
Explanation:
First, we should find the kinetic energy of the bullet is:

with m the mass and v the velocity.

Now we know that half of the kinetic energy of the bullet is transformed into internal energy, by second's law of thermodynamics that means heat (Q) to raise bullet temperature (T), so:

To know what the increase in temperature is, we should use specific heat of lead:

The equation that relates specific heat, change in temperature and mass is:

solving for
:


Answer:
Explanation:
Let pressure at surface of earth be P Pa.
pressure at height of 8.1 km in air can be calculated as follows .
pressure due to column of air of 8.1 km height
= h d g , h is height , d is density of air and g is acceleration due to gravity
= 8.1 x 1000 x .87 x 9.8 = 6.9 x 10⁴ Pa .
pressure at the height of 8.1 km
= P - 6.9 x 10⁴ Pa
Pressure due to column of 16 m in the sea
= h d g
16 x 1000 x 9.8
= 15.68 x 10⁴ Pa .
Pressure at depth of 16m
= P + 15.68 x 10⁴
pressure difference between points at height of 8.1 km and pressure at point 16 m deep
= P + 15.68 x 10⁴ - P + 6.9 x 10⁴ Pa
= 22.58 x 10⁴ Pa .
Answer:
F' = 800 N
Explanation:
The electrical force between charges is 400 N.
The electrical force between two charges is given by :

If q₁' = 2q₁, new force becomes,

So, the new force becomes 800 N.
As per the question the wavelength of spectral line of the neutral hydrogen atom is 21 cm.
Spectral line of hydrogen atom will be observed when an electron will jump from higher excited to the ground state. If E is the energy of the ground state and E' is the energy of the higher excited state,the energy emitted when electron will jump from higher excited to ground state is E'-E.
As per Planck's quantum theory -

Where f is the frequency of emitted radiation and h is the Planck's constant.Actually this energy emitted is also electromagnetic in nature. We know that all the electromagnetic radiation will move with the same velocity which is equal to the velocity of light.
The velocity of light c= 3×10^8 m/s.Hence the velocity of wave corresponding to this spectral line is 3×10^8 m/s.
We know that velocity of a wave is the product of frequency and wavelength of that corresponding wave. Mathematically we can write it as-

[
is the wavelength of the wave ]
It is given that wavelength =21 cm=0.21 m
The frequency is calculated as -




Hence the antenna will be tuned to a frequency of 14.2857×10^8 Hz
Here Hertz[ Hz] is the unit of frequency.