9. CALCULATE: How much more power is used to move a weight of 500 N a distance of 20 m in 5 s than is used to move a weight of 1
2 answers:
You might be interested in
Answer:
1. 3
2. 1.5
3. 3 seconds
4. 0
5. 2.2 seconds
Explanation:
(1)
From v= u + at where v is final velocity, u is initial velocity, a is acceleration and t is time.
Making a the subject we have
Substituting u=0 since it’s at rest, v=30m/s and t=10 seconds
a =
(2)
From v= u + at where v is final velocity, u is initial velocity, a is acceleration and t is time.
Making a the subject we have
Substituting u=10m/s, v=22m/s and t=8 seconds
a =
(3)
From v= u + at where v is final velocity, u is initial velocity, a is acceleration and t is time.
Making t the subject we have
Substituting u=0m/s since at rest, v=15m/s and a=5
=
(4)
When initial and final velocity are constant, there’s no acceleration as proven below
From v= u + at where v is final velocity, u is initial velocity, a is acceleration and t is time.
Making a the subject we have
Substituting u=20 since it’s at rest, v=20m/s and t=10 seconds
a =
(5)
From v= u + at where v is final velocity, u is initial velocity, a is acceleration and t is time.
Making t the subject we have
Substituting u=9m/s since at rest, v=0m/s and a=-4.1
=
The relationship between frequency and wavelength for an electromagnetic wave is
where
f is the frequency
is the wavelength
is the speed of light.
For the light in our problem, the frequency is
, so its wavelength is (re-arranging the previous formula)
where
f is the frequency
For the light in our problem, the frequency is