a book,initially at rest is pushed along a horizontal table top by a horizontal force of 2N. After 1s it has been moved 1.5m. The force of friction is 0.4N
a.how much work is done on the book by the 2N force?
b.how much work is done on the book by friction?
c.what is the books kinetic energy after 1s?
d.what power is required?
work done=2.0*1.5
friction=.4*1.5
in 1 secnod, it goes 1.5 m
KE=work done-friction=1.6*1.5 joules
power=KE/time=1.6*1.5/1 watts
To find the answers to these questions, let's break down the problem step by step.
a. How much work is done on the book by the 2N force?
Work is equal to the product of the force applied and the displacement. In this case, the force applied is 2N and the displacement is 1.5m. So, the work done can be calculated as:
Work = Force × Displacement
= 2N × 1.5m
= 3 Joules (J)
Therefore, 3 Joules of work is done on the book by the 2N force.
b. How much work is done on the book by friction?
Work done by friction can be calculated using the formula:
Work = Force × Displacement
= 0.4N × 1.5m (since the displacement is the same as in the previous question)
= 0.6 Joules (J)
Therefore, 0.6 Joules of work is done on the book by friction.
c. What is the book's kinetic energy after 1s?
The work done on an object is equal to the change in its kinetic energy. Therefore, the total work done on the book (by the 2N force and friction) will result in an increase in the book's kinetic energy.
Kinetic energy can be calculated using the formula:
Kinetic Energy = 0.5 × mass × velocity^2
Since the book starts from rest, the initial velocity is 0. After 1s, assuming there is no other force acting on the book apart from the 2N force and friction, the book's velocity would be:
Velocity = Displacement / Time
= 1.5m / 1s
= 1.5 m/s
Now, we can calculate the change in kinetic energy:
Change in Kinetic Energy = Total Work Done on the Book
= Work done by 2N force + Work done by Friction
= 3J + 0.6J
= 3.6 Joules (J)
Therefore, after 1s, the book's kinetic energy increases by 3.6 Joules.
d. What power is required?
Power is the rate at which work is done or the amount of work done per unit time. It can be calculated using the formula:
Power = Work / Time
From the previous question, we know that the work done on the book after 1s is 3 Joules. So, the power required can be calculated as:
Power = 3J / 1s
= 3 Watts (W)
Therefore, the power required is 3 Watts.