If the angle is either 0 or 180, that means that there is either negative or positive work, so A and D are not correct.
If the angle is 45, then there is still some work involved.
The only option where there is no work done by a force is B. when the angle is between the force and displacement is 90.
Answer:
When two forces acting on an object are equal in size but act in opposite directions, we say that they are balanced forces.
Explanation:
Upward and downward forces cancel out. Net force is 8 newtons to the right
Answer:
Power = 0.33 Watts
Explanation:
Given the following data;
Distance = 1m
Force = 20N
First of all, we would solve for the work done by the boy.
Workdone = force * distance
Substituting into the equation, we have;
Workdone = 20*1 = 20J
Now to find power;
Power = workdone/time
Power = 20/60
Power = 0.33 Watts.
Answer:
100,800 Jkg
The heat that is used to change the state of a mater is called latent heat.
In this case it is converting ice to water and it is called latent heat of fusion.
It is given by:
Heat = mc
where m is the mass of ice and l is the specific latent heat of fusion of ice.
l = 0.336 MJ
Heat = 0.3 × 0.336 MJ
= 0.3 × 0.336 × 10⁶
= 100,800 Jkg
