Answer: 2700 Joules
Explanation:
Given variables are:
Workdone (w) = ?
Weight of sack (w) = 15N
Time taken (t) = 3 minutes
The standard unit of time is seconds, so convert 3 minutes to seconds
(If 1 minute = 60 seconds
3 minutes = 3 x 60 = 180 seconds)
Recall that work is done is when force is applied on an object over a distance
i.e Workdone = force x distance.
(However, the force acting on the sack of potatoes is weight)
Hence, workdone = weight x time
w = 15N x 180 seconds
w = 2700 J
thus, 2700 joules of work was done.
Answer : The final temperature of the mixture is 
Explanation :
First we have to calculate the mass of water.
Mass = Density × Volume
Density of water = 1.00 g/mL
Mass = 1.00 g/mL × 180 cm³ = 180 g
In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.
where,
= specific heat of hot water (liquid) = 
= specific heat of ice (solid)= 
= mass of hot water = 180 g
= mass of ice = 20 g
= final temperature of mixture = ?
= initial temperature of hot water = 
= initial temperature of ice = 
Now put all the given values in the above formula, we get
Therefore, the final temperature of the mixture is
A hammer pounding a nail into a board is an example of Newton’s Third law.
Newton’s third law states that for every action there is an equal and opposite reaction. Meaning, when you hit the hammer on the board the same amount of energy that is going into the board, is going into the hammer. Causing the hammer to bounce off the board.
Hope this helps!
Answer:26.83secs
Explanation: s= UT + 1/2at^2
U=0
S= 1/2at^2
1800=1/2*5t^2
3600=5t^2
3600/5=t^2
720=t^2
t=√720
t=26.83secs
The answer to this is that it is FALSE!
