Answer:
laser pointer does not make use of total internal reflection
24-15=9 m/s slower in 12 seconds. So 9/12 m/s² slower. Therefore the acceleration is -0,75 m/s²
A )voltage
(i.e differance in electricity field)
Answer:
Approximately
(rounded down,) assuming that
.
The number of repetitions would increase if efficiency increases.
Explanation:
Ensure that all quantities involved are in standard units:
Energy from the cookie (should be in joules,
):
.
Height of the weight (should be in meters,
):
.
Energy required to lift the weight by
without acceleration:
.
At an efficiency of
, the actual amount of energy required to raise this weight to that height would be:
.
Divide
by
to find the number of times this weight could be lifted up within that energy budget:
.
Increasing the efficiency (the denominator) would reduce the amount of energy input required to achieve the same amount of useful work. Thus, the same energy budget would allow this weight to be lifted up for more times.
Answer:
Kinetic energy : "It is the energy possessed by body by virtue of its motion" .
Explanation:
The mechanical energy is the energy that a body has due to its motion or position .
It is of two types :
- Potential energy
- Kinetic energy
Potential energy
"It is the energy that a body has due to its position or state" .
It is given by P.E=mgh
Kinetic energy
"It is the energy that a body has due to its motion" .
The formula is : K.E=1/2mv².
For example
- A ball is placed on table .
- At that time it has potential energy .
- Now,lets say that we push it and it drops down .
- On doing this ,the potential energy of ball gets converted into kinetic energy(because it comes in motion ) and as soon as it touches the ground it stops and its kinetic energy gets converted into Potential energy again .