After the ball leaves the thrower's hand, the only force on it is
due to gravity. There's no horizontal force acting on it at all. (C)
Answer:
B. The mass of Mars is less than the mass of Earth.
Explanation:
Mass of an object is the constant anywhere in the universe.
The weight of an object is equal to the gravitational force acting on it.
Weight is given by

where
G = Gravitational constant
M = Mass of Planet
R = Radius of planet
m = Mass of object
g = Acceleration due to gravity
So weight of an object depends on the acceleration due to gravity on that planet. The acceleration due to gravity depends on the mass and radius of the planet.
The weight of the object is less on Mars because mars has less mass compared to Earth.
Well, those are good ones. Now how about a <u><em>thermometer</em></u> to <em>measure the temperature</em> ?
Answer:
The average velocity is 50 km/h south
Explanation:
The average velocity of an object is its total displacement divided by
the total time taken.
That means it is the rate at which an object changes its position from
one place to another.
Average velocity is a vector quantity.
The SI unit is meters per second.
A bicycle that starts 100 km south and is 120 km south of town after
0.4 hour.
The displacement = 120 - 100 = 20 km south
The time = 0.4 hour
The average velocity =
, where D is the displacement
and t is the time
The average velocity of the bicycle =
km/h
<em>The average velocity is 50 km/h south</em>
If you want it in meter per second, change the kilometer to meter
and change the hour to seconds
1 km = 1000 m
1 hour = 60 × 60 = 3600 seconds
The average velocity of the bicycle =
m/s south