Answer:
- a.

- b.

- c.

Explanation:
The spacetime interval
is given by

please, be aware this is the definition for the signature ( + - - - ), for the signature (- + + + ) the spacetime interval is given by:
.
Lets work with the signature ( + - - - ), and, if needed in the other signature, we can multiply our interval by -1.
<h3>a.</h3>





so


<h3>b.</h3>





so


<h3>c.</h3>





so


Answer:Racquet force is twice of Player force
Explanation:
Given
ball arrives at a speed of 
ball returned with speed of 
average Force imparted by racquet on the ball is given by

where 
time of contact of ball with racquet


When it land on the player hand its final velocity becomes zero and time of contact is same as of racquet


From 1 and 2 we get

Hence the magnitude of Force by racquet is twice the Force by player
120 minutes=2 hours
20/2= 10mph
Answer: The Boston Tea Party was a political protest that occurred on December 16, 1773, at Griffin’s Wharf in Boston, Massachusetts. American colonists, frustrated and angry at Britain for imposing “taxation without representation,” dumped 342 chests of tea, imported by the British East India Company into the harbor. The event was the first major act of defiance to British rule over the colonists. It showed Great Britain that Americans wouldn’t take taxation and tyranny sitting down, and rallied American patriots across the 13 colonies to fight for independence.
Explanation: brainlest please