Answer:
3.68 m/s
Corrected question;
Chef Andy tosses an orange in the air, then catches it again at the same height. The orange is in the air for 0.75 s. We can ignore air resistance. What was the orange's velocity at the moment it was tossed into the air?
Explanation:
Applying the equation of motion;
v = u + at. ....1
Where
u = initial speed
v = final speed
a = acceleration
t = time taken
Given;
Total time of flight t = 0.75s
Acceleration due to gravity g = 9.8 m/s^2
Considering the first phase of flight, during the upward motion to the maximum height. The final velocity at the maximum height is zero and the time of flight of the phase is equal to half of the total flight time.
v1 = 0
t1 = t/2 = 0.75/2 =0.375s
From equation 1;
v1 = u - gt1
Substituting the values;
0 = u - 9.8(0.375)
Solving for u;
u = 9.8(0.375)
u = 3.675
u = 3.68 m/s
Initial velocity = 3.68 m/s
Answer:
470.4N
Explanation:
Given parameters:
Mass of the skydiver = 48kg
Unknown:
Force she exerts as she is falling to the ground = ?
Solution:
The force she exerts while falling to the ground is her weight;
Weight = mass x acceleration due to gravity
Acceleration due to gravity = 9.8m/s²
Weight = 48 x 9.8 = 470.4N
You have
1
s
, and oftentimes with wavelength, you want to convert to
nm
which is UV-Vis range (
200~700 nm
), and is often of spectral interest.
What you want to do is:
1
s
→
1
m
→
m
→
nm
Conversion factors are extremely useful, and one easy one to remember is the speed of light, which is about
3
×
10
8
m/s
.
1
1
s
⋅
s
m
=
m
And finally, we can convert to
nm
:
10
9
nm
=
1 m
→
conversion factor:
10
9
nm
1 m
m
⋅
10
9
nm
1
m
Thus, overall, you just have:
nm
=
1
1
s
⋅
s
3
×
10
8
m
⋅
10
9
nm
1
m
=
1
1
/
s
⋅
3
×
10
8
m
/
s
×
10
9
nm
1
m