Answer:
a) T = 2.26 N, b) v = 1.68 m / s
Explanation:
We use Newton's second law
Let's set a reference system where the x-axis is radial and the y-axis is vertical, let's decompose the tension of the string
sin 30 = 
cos 30 = 
Tₓ = T sin 30
T_y = T cos 30
Y axis
T_y -W = 0
T cos 30 = mg (1)
X axis
Tₓ = m a
they relate it is centripetal
a = v² / r
we substitute
T sin 30 = m
(2)
a) we substitute in 1
T = 
T = 
T = 2.26 N
b) from equation 2
v² = 
If we know the length of the string
sin 30 = r / L
r = L sin 30
we substitute
v² = 
v² = 
For the problem let us take L = 1 m
let's calculate
v = 
v = 1.68 m / s
Answer:
7.04 m
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity = 0
s = Displacement on Earth = 1.2 m
a = Acceleration due to gravity on Moon = 1.67 m/s²
a = Acceleration due to gravity Earth= 9.81 m/s²
Accelration going up is considered as negetive
Initial Velocity of the ball
Assuming that the ball is thrown with the same velocity on the Moon, displacement of the ball is
The displacement of the ball on the moon is 7.04 m
The spider is traveling in a circle with radius = 15cm
The circumference of any circle = <em>2 pi (radius)</em>
The circumference of the spider's path = 2 pi (15 cm) = 30 pi cm
The spider completes a trip around this path 78 times per minute.
Its speed, relative to you, is
(78) x (30 pi) cm/min =
2,340 pi cm/min = 7,351.33 cm/min =
<em> 73.5133 meter/min =</em>
<em>4.411 km/hr =</em>
<em>2.74 miles/hour
</em>(After the last appearance of pi,
all numbers are rounded.)<em>
</em>
