Given data:
* The mass of the ball is 2 kg.
* The gravitational field strength at the surface of planet X is 5 N/kg.
Solution:
The weight of the ball on the planet X is,

where m is the mass of ball, a is the gravitational field strength,
Substituting the known values,

Thus, the weight of the ball on the surface of planet X is 10 N.
We want to find the combined volume of 3 tennis balls. We will get that the combined volume is 493.7 cm^3
First, remember that for a sphere of diameter D, the volume is:

Where 3.14 is pi.
Here we know that the average diameter of a tennis ball is 6.8cm, then we can replace that in the above equation to find the volume (in average) of a single tennis ball:

Now, in 3 balls of tennis, the combined volume will be 3 times the above one, this is:

If you want to learn more about volumes, you can read:
brainly.com/question/10171109
Answer:
<h2> 27m/s</h2>
Explanation:
Given data
initital velocity u=15m/s
deceleration a=3m/s^2
time t= 4 seconds
final velocity v= ?
Applying the expression
v=u+at------1
substituting our data into the expression we have
v=15+3*4
v=15+12
v=27m/s
The velocity after 4 seconds is 27m/s