Consider the upward direction of motion as positive and downward direction of motion as negative.
a = acceleration due to gravity in downward direction = - 9.8
v₀ = initial velocity of rock in upward direction = ?
v = final velocity of rock at the highest point = 0
t = time to reach the maximum height = 4.2 sec
Using the kinematics equation
v = v₀ + a t
inserting the values
0 = v₀ + (- 9.8) (4.2)
v₀ = 41.2
Answer:
ΔV=0.484mV
Explanation:
The potential difference across the end of conductor that obeys Ohms law:
ΔV=IR
Where I is current
R is resistance
The resistance of a cylindrical conductor is related to its resistivity p,Length L and cross section area A
R=(pL)/A
Given data
Length L=3.87 cm =0.0387m
Diameter d=2.11 cm =0.0211 m
Current I=165 A
Resistivity of aluminum p=2.65×10⁻⁸ ohms
So
ΔV=IR
ΔV=0.484mV
Answer:
Explanation:
Since the pulley has a mass concentrated on its rim, the pulley can be considered as a ring.
The moment of inertia of a ring is
The mass on the left is heavier, that is the pulley is rotating counterclockwise.
By Newton's Second Law, the net torque is equal to moment of inertia times angular acceleration.
Here, the net torque is the sum of the weight on the left and the weight on the right.
Applying Newton's Second Law gives the angular acceleration
The relation between angular acceleration and linear acceleration is
Then, the linear acceleration of the masses is