Maybe show a picture ? I don’t get the question .
Answer:
Option (A) and (F)
Explanation:
As the liquid cools down, it means the temperature decreases the density of the liquid increases in most o the cases.
Now the volume is inversely proportional to the density of substance so density increases.
Answer:
a) 25.5°(south of east)
b) 119 s
c) 238 m
Explanation:
solution:
we have river speed =2 m/s
velocity of motorboat relative to water is =4.2 m/s
so speed will be:
a) =+
solving graphically
=4.7 m/s
Ф=
=25.5°(south of east)
b) time to cross the river: t===119 s
c) d==(2)(119)=238 m
note :
pic is attached
a)
We use the formula :
m1v1i + m2v2i = m1v1f + m2v2f
Substituting the values in:
4.0kg*8.0m/s + 4.0kg*0m/s = 4.0kg*0m/s +4.0kg*v2f
Calculating this we get:
32.0kg*m/s + 0kg*m/s = 0kg*m/s + 4.0kg*v2f
Rearrange for v2f:
v2f =
This gives us 8.0 m/s as the final velocity of the second ball.
b)
Since the collision is assumed to be elastic it means that the kinetic energy must be equal before and after the collision.
This means we use the formula:
Ek = + = +
Substituting in values:
Ek = 0.5*4.0kg*(8.0m/s)^2 + 0.5*4.0kg*(0m/s)^2 = 0.5*4.0kg*(0m/s)^2 + 0.5*4.0kg*(8.0m/s)^2
This simplifies to:
Ek= 128J + 0J = 0J + 128J
This shows us that the kinetic energy is equal on each side therefore the collision is Elastic and no energy has been lost.