The average force on the ball by the racket is 98 N. The correct option is the third option - 98 N
From the question, we are to determine the average force on the ball by the racket.
From the formula,

Where F is the force
m is the mass
v is the velocity
and t is the time
From the given information
m = 0.07 kg
v = 56 m/s
t = 0.04 s
Putting the parameters into the formula,
we get


F = 98 N
Hence, the average force on the ball by the racket is 98 N. The correct option is the third option - 98 N
Learn more on calculating force exerted on an object here: brainly.com/question/13590154
Your answer is infrared, visible, ultraviolet.
Since everything in the circuit is in series .. .
-- The total resistance is (3 + 2) = 5 ohms.
-- The voltage across the 3-ohm resistor is 3/5 of the total voltage.
-- The voltage across the 2-ohm resistor is 2/5 of the total voltage.
(2/5) of (9 volts) = 18/5 = 3.6 volts .
Answer:
a. 
b. 
Explanation:
I have attached an illustration of a solid disk with the respective forces applied, as stated in this question.
Forces applied to the solid disk include:

Other parameters given include:
Mass of solid disk, 
and radius of solid disk, 
a.) The formula for determining torque (
), is 
Hence the net torque produced by the two forces is given as a summation of both forces:

b.) The angular acceleration of the disk can be found thus:
using the formula for the Moment of Inertia of a solid disk;

where
= Mass of solid disk
and
= radius of solid disk
We then relate the torque and angular acceleration (
) with the formula:

Motion of a ball thrown by a person upwards and caught after some time is an example of motion in which displacement of the particle is zero but acceleration is not zero in journey.
The displacement of the ball is zero because the starting and end point of the motion are same, i.e, the person's hands.During its motion, the acceleration of ball is constant and non zero called as acceleration due to gravity, g= -9.8 m/s². The velocity of ball is continuously changing. It first decreases during the upward motion of the ball and then increases during the downward journey.The acceleration remains constant and non zero all the time.