After a short time, the moving sled with the child aboard reached a rough level surface that exerts a constant frictional force
of 54 Newtons on the sled. How much work must be done by friction to bring the sled with the child to a stop
2 answers:
Answer:
Wf = –750J
Explanation:
The full solution can be found in the attachment below.
This problem involves the concepts of conservation of momentum and energy.
The potential energy of the sled and child combined is constant since thehy are moving in a level surface.
To find the initial velocity of the sled with child we use the principle of momentum conservation to calculate the v1 which is the commovelocity of the child and sled.
You might be interested in
Explanation:
The speed of a wave is given by :
......(1)
(i) Here, the wavelength of a sound wave in air reduces by a factor of 3. Equation (1) becomes :
Wavelength and frequency are inversely proportional to each other. So, if wavelength of a sound wave in air reduces by a factor of 3, then the frequency will increases by a factor of 3.
(ii) It remains the same.
Answer:
I = 2172.46 A
Explanation:
Given that,
The length of a solenoid, l = 2.1 m
The inner radius of the solenoid, r = 28 cm = 0.28 m
The number of turns in the wire, N = 1000
The magnetic field in the solenoid, B = 1.3 T
We need to find the current carried by it. We know that, the magnetic field in a solenoid is given by :
Put all the values,
So, it carry current of 2172.46 A.