Answer:
0.29
Explanation:
We can find the position of the image by using the mirror equation:

where:
f is the focal length of the mirror
p is the distance of the object from the mirror
q is the distance of the image from the mirror
For the mirror in this problem:
f = -12.7 cm (the focal length of a convex mirror is negative)
p = 31.3 cm (distance of the object)
Solving for q, we find the position of the image:

And so, the magnification of the image is:

And substituting,

Which means that the image is upright (positive sign) and diminished (M is smaller than 1).
Answer: See explanation
Explanation:
The density would like be calculated by dividing the mass by volume. This will be:
Density = Mass / Volume
Density = 390 / 50
Density = 7.8g/cm
Answer: catching the ball is a better choice.
Explanation:
The collision of 2 objects involves involves large impact force since the force is inversely proportional to the time in which the momentum of the object changes.
Mathematically

If we catch the ball we increase the time in which the momentum of the ball is decreased thus the impact force that acts on us is lower as larger time is allowed for the ball to decrease it's momentum.
If we allow the ball to hit us the momentum of the ball changes in a short period of time thus applying a large impact force on our body thus increasing the chances of toppling.
50 g of liquid X at 10 Celcius and 200 g of liquid Y
mx*cx*(t-tx)+my*cy*(t-ty)=0
cx/cy = - my*(t-ty) : mx*(t-tx) = (my/mx) * (ty - t) / (t-tx)
cx/cy = 200/50*(40-15)/(15-10) = 20
cx/cy = 20
During the first phase of acceleration we have:
v o = 4 m/s; t = 8 s; v = 13 m/s, a = ?
v = v o + a * t
13 m/s = 4 m / s + a * 8 s
a * 8 s = 9 m/s
a = 9 m/s : 8 s
a = 1.125 m/s²
The final speed:
v = ?; v o = 13 m/s; a = 1.125 m/s² ; t = 16 s
v = v o + a * t
v = 13 m/s + 1.125 m/s² * 16 s
v = 13 m/s + 18 m/s = 31 m/s