Answer:
A. Acceleration always involves changing speed.
Explanation:
Acceleration is defined as the rate of change of velocity.
Velocity is a vector quantity and is defined as speed in a given direction. Therefore, when any or both of the components of velocity is changing with time, a body is said to be accelerating i.e. acceleration involves a change of speed or change in direction, or a change in both speed and direction.
Considering the statements:
A. Acceleration always involves changing speed is false because acceleration can occur when speed is constant but direction is changing.
B. Changing direction always involves acceleration is true because, a change in direction results in a change in velocity.
C Changing speed always involves acceleration is true because, changing speed results in a change in velocity.
D. Circular motion always involves acceleration is true because in circular motion the direction is always changing, and this results in a change in velocity
3 Newtons toward the right because Newton’s second law:
F = ma
15N - 12N = ma
3N = ma
(With the right being the positive direction and the left the negative direction)
Answer:
Marine geologists learn about the rocks and geologic processes of the ocean basins.
The continuious physical force per unit area that one region of a gas, liquid, or solid exerts on another.
Answer:
x = 41.28 m
Explanation:
This is a projectile launching exercise, let's find the time it takes to get to the base of the cliff.
Let's start by using trigonometry to find the initial velocity
cos 25 = v₀ₓ / v₀
sin 25 = Iv_{oy} / v₀
v₀ₓ = v₀ cos 25
v_{oy} = v₀ sin 25
v₀ₓ = 22 cos 25 = 19.94 m / s
v_{oy} = 22 sin 25 = 0.0192 m / s
let's use movement on the vertical axis
y = y₀ + v_{oy} t - ½ g t²
when reaching the base of the cliff y = 0 and the initial height is y₀ = 21 m
0 = 21 + 0.0192 t - ½ 9.81 t²
4.905 t² - 0.0192 t - 21 = 0
t² - 0.003914 t - 4.2813 =0
we solve the quadratic equation
t = 
t = 
t₁ = 2.07 s
t₂ = -2.067 s
since time must be a positive scalar quantity, the correct result is
t = 2.07 s
now we can look up the distance traveled
x = v₀ₓ t
x = 19.94 2.07
x = 41.28 m
