Answer:
98J
Explanation:
Given parameters:
Mass of rock = 5kg
Height = 2m
Unknown:
Work done = ?
Solution:
The amount of work done is given as:
Work done = Force x distance
Work done = Weight x height
Work done = mgH
Now insert the parameters and solve;
Work done = 5 x 9.8 x 2 = 98J
Answer:
178 cm3
Explanation:
From definition of density, it is mass per unit volume of an object, expressed as density=mass/volume and making volume the subject of the above formula we have volume= mass/density and substituting 0.00296 g for mass and 0.00001663 g/cm3 for density then we have
Volume=0.00296/0.00001663
Volume is approximately 178 cm3
Answer:
v (minimum speed) = 2.90 m/sec.

Maximum value of speed will occur at lowest point of vertical circle.
Explanation:
a) What minimum speed is necessary so that there is no tension in the string at the top of the circle but the rock stays in the same circular path?
Using the force balance expression at the top of the circle,
Gravitational Force + Tension force = Centrifugal force

Given that : T = 0
R = length of string = 0.86 m
mass of the spinning rock = 0.75 kg


v (minimum speed) = 2.90 m/sec.
b) what is the maximum speed the rock can have so that the string does not break?
Here the force balance at bottom of circle is represented by the illustration:

Given that:
maximum tension T = 45 N
maximum speed v = ??
mass m = 0.75 kg
∴

c)
At what point in the vertical circle does this maximum value occur?
Maximum value of speed will occur at lowest point of vertical circle.
This is so because at the lowest point; the tension in string will be maximum.
Answer:
0.5 , 54.5
Explanation:
for acceleration we should derivate the equation 2 times
x=3t³+t²/4
v=9t²+t/2
a=18t+1/2
a(0)=0.5
a(3)=54.5