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:
12.4 m/s²
Explanation:
L = length of the simple pendulum = 53 cm = 0.53 m
n = Number of full swing cycles = 99.0
t = Total time taken = 128 s
T = Time period of the pendulum
g = magnitude of gravitational acceleration on the planet
Time period of the pendulum is given as


T = 1.3 sec
Time period of the pendulum is also given as


g = 12.4 m/s²
Answer:

Explanation:
In order to convert the work function of cesium from electronvolts to Joules, we must use the following conversion factor:

In our problem, the work function of cesium is

so, we can convert it into Joules by using the following proportion:

Answer:
The index of refraction of the glass is 1.3
Explanation:
Given data:
i = incident angle = 50°
r = refracted angle = 36.1°
The index of refraction according Snell´s law is:

Use of lubricant
Use of ball bearers
Use of streamlined body
Use of graphite