Answer:
1. Electromagnetic waves travel in a vacuum whereas mechanical waves do not.
2. The ripples made in a pool of water after a stone is thrown in the middle are an example of mechanical wave. Examples of electromagnetic waves include light and radio signals.
3. Mechanical waves are caused by wave amplitude and not by frequency. Electromagnetic Waves are produced by vibration of the charged particles.
4. While an electromagnetic wave is called just a disturbance, a mechanical wave is considered a periodic disturbance.
Explanation:
Answer:60 gm
Explanation:
Given
initial velocity of ball 
Force exerted by racquet 
time period of force 
final velocity of ball 
Racquet imparts an impulse to the ball which is given by



The formula that links voltage (V), resistance (R) and current intensity (I) is

Solve this formula for I to get

Plug your values for V and R and you'll get the current.
It's b, because the more force an object it is given the harder it will be for it to slow down.
Answer:
<h2>470.59 kg</h2>
Explanation:
The the mass of the car can be found by using the formula

f is the force
a is the acceleration
From the question we have

We have the final answer as
<h3>470.59 kg</h3>
Hope this helps you