Answer:
Explanation:
given,
refractive index of lens, n = 1.70
Radius of curvature of front surface. R₁ = 20 cm
Radius of curvature of the back surface, R₂ = 30 cm
focal length= ?
R₁ = +20 cm
R₂ = -30 cm
n = 1.70
the focal length of the lens is equal to 17.15 cm
By Snell's law:
η = sini / sinr. i = 25, η = 1.33
1.33 = sin25° / sinr
sinr = sin25° / 1.33 = 0.4226/1.33 = 0.3177 Use a calculator.
r = sin⁻¹(0.3177)
r ≈ 18.52°
Option A.
God's grace.
Answer:
The distance is
=
7
m
Explanation:
Apply the equation of motion
s
(
t
)
=
u
t
+
1
2
a
t
2
The initial velocity is
u
=
0
m
s
−
1
The acceleration is
a
=
2
m
s
−
2
Therefore, when
t
=
3
s
, we get
s
(
3
)
=
0
+
1
2
⋅
2
⋅
3
2
=
9
m
and when
t
=
4
s
s
(
4
)
=
0
+
1
2
⋅
2
⋅
4
2
=
16
m
Therefore,
The distance travelled in the fourth second is
d
=
s
(
4
)
−
s
(
3
)
=
16
−
9
=
7
m
Answer:
16250 kgm/s due south
Explanation:
Applying,
M = mv................. Equation 1
Where M = momentum, m = mass, v = velocity.
From the car,
Given: m = 1000 kg, v = 6.5 m/s
Substitute these values into equation 1
M = 1000(6.5)
M = 6500 kgm/s
For the truck,
Given: m = 3500 kg, v = 6.5 m/s
Substitute these values into equation 1
M' = 3500(6.5)
M' = 22750 kgm/s.
Assuming South to be negative direction,
From the question,
Total momentum of the two vehicles = (6500-22750)
Total momentum of the two vehicles = -16250 kgm/s
Hence the total momentum of the two vehicles is 16250 kgm/s due south
1.8 is the mechanical advantage of the lever.
<h3>Definition of mechanical advantage</h3>
The theoretical mechanical advantage of a system is the ratio of the force that performs the useful work to the force applied, assuming there is no friction in the system.
The advantage gained by the use of a mechanism in transmitting force specifically the ratio of the force that performs the useful work of a machine to the force that is applied to the machine.
Mechanical advantage is given by the ratio of the load lifted to the force applied to lift the load.
In this case, Mechanical advantage=L/E where L is the load and E is the effort applied.
Mechanical advantage= 90/50 =1.8
Question-you use a lever to lift a heavy tree branch. you apply a force of 50 n and the lever lifts the branch with a force of 90 n. what is the mechanical advantage of the lever?
To learn more about the Mechanical advantage visit the link
brainly.com/question/16617083
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