Answer:
The momentum is 1.94 kg m/s.
Explanation:
To solve this problem we equate the potential energy of the spring with the kinetic energy of the ball.
The potential energy
of the compressed spring is given by
,
where
is the length of compression and
is the spring constant.
And the kinetic energy of the ball is

When the spring is released all of the potential energy of the spring goes into the kinetic energy of the ball; therefore,

solving for
we get:

And since momentum of the ball is
,

Putting in numbers we get:


Answer:
The focal length of the mirror is 52.5 cm.
Explanation:
Given that,
Object to Image distance d = 140 cm
Image distance v= 35 cm
We need to calculate the object distance


We need to calculate the focal length
Using formula of mirror

Put the value into the formula



Hence, The focal length of the mirror is 52.5 cm.
Answer:
Weight=686.7N,
, S.G.=0.933, F=17.5N
Explanation:
So, the first value the problem is asking us for is the weight of methanol. (This is supposing there is a mass of methanol of 70kg inside the tank). We can find this by using the formula:
W=mg
so we can substitute the data the problem provided us with to get:

which yields:
W=686.7N
Next, we need to find the density of methanol, which can be found by using the following formula:

we know the volume of methanol is 75L, so we can convert that to
like this:

so we can now use the density formula to find our the methanol's density, so we get:



Next, we can us these values to find the specific gravity of methanol by using the formula:

when substituting the known values we get:

so:
S.G.=0.933
We can now find the force it takes to accelerate this tank linearly at 
F=ma

F=17.5N
Answer:
Bullying in the schools has negative effects on individual students and on the school climate as a whole. Bullying can cause long-term problems for both the victims of bullying and the bullies themselves. To explore the effects of bullying on adolescents, we will define bullying, identify the characteristics of bullies and victims, outline the extent and consequences of bullying, and present resources for further information and assistance.
Bullying is any behavior that is initiated by one or more students against a victim or victims that causes physical or psychological intimidation. Bullying behaviors can be classified as either direct (such as teasing, threatening, hitting, or stealing) or indirect (such as rumor spreading or social isolation). Boys typically employed direct methods of bullying, while girls tend to use in direct methods. Either way, behaviors must occur repeatedly overtime to be classified as bullying.
Characteristics of Bullies and Victims
There are specific behaviors that bullies tend to exhibit. The bullies often need to feel powerful and in control. They may feel no remorse when they inflict injury and suffering on others. Bullies tend to defy authority and are likely to break school rules. They seem to have little anxiety and appear to possess high self-esteem. Students who come from homes characterized by physical punishment tend to be more likely to exhibit these types of behaviors.
Victims also tend to exhibit specific characteristics. They are often anxious, insecure, cautious, and have low self-esteem. Victims tend to be socially isolated, and may lack social skills and friends. Because they tend to be weaker than their peers, either physically or socially, victims rarely retaliate against bullies. Students who have close ties with their parents/guardians or who have overprotective parents/guardians are more likely to be victimized by bullies.
Power = Work/time
Work= energy
Potential energy =mxgxh
Power=mxgxh/t
Power=68x10x7/9
Power=529 watts