5.38
21 divided by 3.9 is 5.38 and the equation for acceleration is change in velocity divided by time
Answer:
(1) Initial speed, 
Final speed, 
Average speed, 
(2) Force of gravity, 
Explanation:
(1)
Given,
Distance, 
Time, 
It is given that drag racer started at rest.
So Initial speed, 
Using Newton's second equation of motion,

Newton's first equation of motion,

So, Final speed, 
Average speed is defined as totle distance divided by totle time.

So, Average speed, 
(2)
Gravitation: It is the natural phenomenon in which two different bodies attract each other by virtue of their masses.
According to Newton's law of gravitation, the force of attraction between two bodies is directly proportional to the masses of the bodies and inversely proportional to square of distance between centers of mass of the bodies.
where
is constant of proportionality and known as gravitation constant.
Given,
Mass of Jupiter, 
Mass of Ganymede, 
Distance between their centers of mass, 

So, Force of gravity, 
Answer:
Mass of the planet = 1.48 × 10²⁵ Kg
Mass of the star = 5.09 × 10³⁰ kg
Explanation:
Given;
Diameter = 1.8 × 10⁷ m
Therefore,
Radius =
=
or
Radius of the planet = 0.9 × 10⁷ m
Rotation period = 22.3 hours
Radius of star = 2.2 × 10¹¹ m
Orbit period = 407 earth days = 407 × 24 × 60 × 60 seconds = 35164800 s
free-fall acceleration = 12.2 m/s²
Now,
we have the relation
g =
g is the free fall acceleration
G is the gravitational force constant
M is the mass of the planet
on substituting the respective values, we get
12.2 =
or
M = 1.48 × 10²⁵ Kg
From the Kepler's law we have
T² =
on substituting the respective values, we get
35164800² =
or
= 5.09 × 10³⁰ kg
Answer:
20 N exerts no torque about the pivot.
14 N exerts a counterclockwise torque of 14 * .3 = .42 N-m
6 exerts a clockwise torque of 6 * .7 = .42 N-m
The meter stick will not turn because there is no net torque on the meter stick.