Answer:
10.86 N
Explanation:
Let the average frictional force acting on the toboggan be 'f' N.
Given:
Mass of toboggan (m) = 19.0 kg
Initial velocity (u) = 4.00 m/s
Final velocity (v) = 0 m/s
Time for which friction acts (Δt) = 7.00 s
Now, change in momentum is given as:
Now, we know that, change in momentum is equal to the impulse acting on the body. So,
Impulse is, 
Now, we know that, impulse is also given as the product of average force and the time interval for which it acts. So,
Rewriting the above equation in terms of 'f', we get:
Plug in the given values and solve for 'f'. This gives,
Therefore, the magnitude of frictional force is 
To obtain the vertical component of the velocity, it is necessary to multiply the velocity at this time by sin 45 degrees. Since the velocity is not given, it must be solved first by dividing the distance by the time. To show this:
Velocity = distance / time
Velocity = 30 m / 4s
Velocity = 7.5 m/s
Vertical velocity = 7.5 sin 45
Vertical velocity = 5.3 m/s
Answer:
Potential energy is the energy that exists by virtue of the relative positions (configurations) of the objects within a physical system.
This form of energy has the potential to change the state of other objects around it, for example, the configuration or motion.
Various forms of energy can be grouped as potential energy.
Each of these forms is associated with a particular kind of force acting in conjunction with some physical property of matter (such as mass, charge, elasticity, temperature etc).
For example, gravitational potential energy is associated with the gravitational force acting on object's mass; elastic potential energy with the elastic force (ultimately electromagnetic force) acting on the elasticity of a deformed object; electrical potential energy with the coulombic force; strong nuclear force or weak nuclear force acting on the electric charge on the object; chemical potential energy, with the chemical potential of a particular atomic or molecular configuration acting on the atomic/molecular structure of the chemical substance that constitutes the object; thermal potential energy with the electromagnetic force in conjunction with the temperature of the object.
For an example of gravitational potential energy, consider a book placed on top of a table.
To raise the book from the floor to the table, work must be done, and energy supplied. (If the book is lifted by a person then this is provided by the chemical energy obtained from that person's food and then stored in the chemicals of the body.) Assuming perfect efficiency (no energy losses), the energy supplied to lift the book is exactly the same as the increase in the book's gravitational potential energy.
The book's potential energy can be released by knocking it off the table.
As the book falls, its potential energy is converted to kinetic energy.
When the book hits the floor this kinetic energy is converted into heat and sound by the impact.
Explanation:
Acceleration is the
rate of change of velocity, a body moving with uniform velocity does not
possess acceleration at all i.e. acceleration is zero
