C. A 1200kg car is going 15m/s
Answer:
#See solution for details.
Explanation:
1.
Tools:
.
:Calculate the speed of the wave using the time,
it takes to travel along the rope. Rope's length,
is measured using the meter stick.
-Attach one end of rope to a wall or post, shake from the unfixed end to generate a pulse. Measure the the time it takes for the pulse to reach the wall once it starts traveling using the stopwatch.
-Speed of the pulse can then be obtained as:

: Apply force of known value to the rope then use the following relation equation to find the speed of a pulse that travels on the rope.

-Use the measuring stick and measuring scale to determine
values of the rope then obtain
.
-Use the force measuring constant to determine
. These values can the be substituted in
to obtain 
The answer is A. Friction.
Friction is the resisting force between two objects that move against one another.
Hope this helps! :)
Answer:
using a formula
average velocity=total displacement/total time
average velocity=120/1minute40sec
1minute=60sec
60sec+40sec=120sec
average velocity=120m/120sec
average velocity=1m/sec
There are two equal forces of gravity between the Earth and the Moon.
One force pulls the Moon toward the Earth.
The other force pulls the Earth toward the Moon.
If only this gravity suddenly switched off, then the moon would
continue to orbit the Sun, very much as it does now.
If ALL gravity suddenly switched off, then . . .
-- the Moon would stop orbiting the Earth and would sail away, in
a straight line and at the speed it had when gravity disappeared;
-- the Earth would stop orbiting the Sun and would sail away, in
a straight line and at the speed it had when gravity disappeared;
-- all the gases surrounding the Earth ... which we call "air" ... would
start drifting away, and expanding into a giant cloud of gas, and stop
being an atmosphere;
-- the Sun would completely fall apart, expand into a giant cloud of gas,
and stop being a star.