'B' and 'C' are both true.
Answer:
Explanation:
It is given that,
Mass of the baseball, m = 0.14 kg
It is dropped form a height of 1.8 m above the ground. Let u is the velocity when it hits the ground. Using the conservation of energy as :
h = 1.8 m
u = 5.93 m/s
Let v is the speed of the ball when it rebounds. Again using the conservation of energy to find it :
h' = 1.4 m
v = -5.23 m/s
The change in the momentum of the ball is given by :
So, the change in the ball's momentum occurs when the ball hits the ground is 1.56 kg-m/s. Hence, this is the required solution.
Answer:
a. 0.21 rad/s2
b. 2.205 N
Explanation:
We convert from rpm to rad/s knowing that each revolution has 2π radians and each minute is 60 seconds
200 rpm = 200 * 2π / 60 = 21 rad/s
180 rpm = 180 * 2π / 60 = 18.85 rad/s
r = d/2 = 30cm / 2 = 15 cm = 0.15 m
a)So if the angular speed decreases steadily (at a constant rate) from 21 rad/s to 18.85 rad/s within 10s then the angular acceleration is
b) Assume the grind stone is a solid disk, its moment of inertia is
Where m = 28 kg is the disk mass and R = 0.15 m is the radius of the disk.
So the friction torque is
The friction force is
Since the friction coefficient is 0.2, we can calculate the normal force that is used to press the knife against the stone
Energy in a machine can be something technical like a wire or something went wrong with the system
Answer:Frequency = 3.525 Hertz
Explanation:In static equilibrium, kd =mg
Where k= effective spring constant of the spring.
mg= The weight of the car.
d= static deflection.
Therefore, w =SQRTg/d
w = SQRT 9.81/0.02
w= 22.15 rad/sec
Converting to Hertz unit for frequency
1 rad/s = 0.1591
22.15rad/s=?
22.15 × 0.1591= 3.525 hertz