><span>It can travel through vacuum.
The rays must travel in the vacuum of space between Earth's atmosphere and the sun.</span>
Answer:
This is because it steps up or steps down electrical voltage. It multiplies either voltage (if it is a voltage transformer )or current (if it is a current transformer), but it does not multiply electrical power.
Explanation:
A transformer steps up or steps down electrical voltage, by transmitting power at a voltage, V₁ and Current I₁ at one terminal, to a voltage, V₂ and Current I₂ at its other terminals, just like a lever transmits force from one point to another. Since the power transmitted remains the same, (energy per unit time remains constant), I₁V₁ = I₂V₂ ⇒ I₁/I₂ = V₂/V₁ = n (the turns ratio of the transformer). So, the turns ratio will determine if its a step-up or step-down transformer. V₂ = nV₁. So, if V₁ > V₂ it is a step down transformer and if V₁ < V₂ it is a step-up transformer.It multiplies either voltage (if it is a voltage transformer )or current (if it is a current transformer), but it does not multiply electrical power, since P = IV = constant for the transformer.
Explanation:
- Newton's first law of motion:
"An object at rest (or in uniform motion) remains at rest (or in uniform motion) unless acted upon an unbalanced force
In this situation, we can apply Newton's first law to the keys of the keyboard that are not hit by the fingers of the man. In fact, as no force act on the keys, they remain at rest.
- Newton's second law of motion:
"The acceleration experienced by an object is proportional to the net force exerted on the object; mathematically:

where F is the net force, m is the mass of the object, and a its acceleration"
In this case, we can apply Newton's second law to the keys of the keyboard that are hit by the man: in fact, as they are hit, they experience a downward force, and therefore they experience a downward acceleration.
"Newton's third law of motion:
"When an object A exerts a force on an object B (action force), then object B exerts an equal and opposite force on object A (reaction force)"
Here We can apply Newton's third law to the pair of objects finger-key: in fact, as the finger apply a force on the key (action force), then the key exerts a force back on the finger (reaction force), equal and opposite.
Density =mass/Volume
0.8=mass/60
Mass=0.8*60
Mass=48g