A., Because speed is constant unless you stop it, or slow down <span />
It’s due to the refraction of light rays as they traverse the boundary between water and air. The greater the viewing angle, the more the bending of the light and therefore the less the apparent depth. An object placed in a denser medium, when viewed from rarer medium appears to be at a lesser depth than its real depth due to refraction of light.
Answer:
Yes, if the carts are travelling into opposite directions
Explanation:
The total momentum of a two carts system is the sum of the momenta of the individual carts:
where
m1, m2 are the masses of the two carts
v1, v2 are the velocities of the two carts
In order to have a total momentum of zero, we must have
(1)
Let's remind that velocity (and so, momentum as well) is a vector quantity: this means that it has a direction, so when summing together the momenta, we must also consider the sign of the velocity, depending on its direction.
Therefore, if the two carts are moving in opposite directions, the signs of the two velocities will be opposite. For example, we can have
This means that the condition in eq.(1) can be satisfied, provided that the two carts are travelling into opposite directions.
The thin atmosphere of Mars is thought to be due to the planet's lack of a magnetic field, which has allowed the Solar wind to blow away much of the gas the planet once had. Venus, despite still having a thick atmosphere of CO2, surprisingly has a similar problem
Answer:
Cool question! First step is to find the time taken to fall
57
m
, then to find the horizontal velocity needed to cover
24
m
in that time. In this case the answer is
7.0
m
s
−
1
.
Explanation:
This is a less typical projectile motion question, but it's still projectile motion. This means the horizontal and vertical directions can be considered separately. We assume that the initial vertical velocity,
u
y
=
0
m
s
−
1
, and we are trying to find the required initial horizontal velocity,
u
x
.
To find the time taken to fall
57
m
:
s
=
u
t
+
1
2
a
t
2
Since
u
=
0
, we can rearrange this to:
t
=
√
2
s
a
=
√
2
⋅
57
9.8
=
3.41
s
The horizontal velocity will be constant (ignoring air resistance), so to cover
24
m
in
3.41
s
will be given by:
v
=
s
t
→
u
x
=
24
3.41
=
7.0
m
s
−
1
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