How many kilocalories are generated when the brakes are used to bring a 1200-kg car to rest from a speed of 95 km/h ? 1 kcal = 4
1 answer:
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Complete Question:
In the "before" part of Fig. 9-60, car A (mass 1100 kg) is stopped at a traffic light when it is rear-ended by car B (mass 1400 kg). Both cars then slide with locked wheels until the frictional force from the slick road (with a low ?k of 0.15) stops them, at distances dA = 6.1 m and dB = 4.4 m. What are the speeds of (a) car A and (b) car B at the start of the sliding, just after the collision? (c) Assuming that linear momentum is conserved during the collision, find the speed of car B just before the collision.
Answer:
a) Speed of car A at the start of sliding = 4.23 m/s
b) speed of car B at the start of sliding = 3.957 m/s
c) Speed of car B before the collision = 7.28 m/s
Explanation:
NB: The figure is not provided but all the parameters needed to solve the question have been given.
Let the frictional force acting on car A, ............(1)
Since frictional force is a type of force, we are safe to say .......(2)
Equating (1) and (2)
a) Speed of A at the start of the sliding
b) Speed of B at the start of the sliding
Let the speed of car B before collision =
Momentum of car B before collision =
Momentum after collision =
Applying the law of conservation of momentum:
Answer:
Explanation:
The interaction of the piece of copper and water means that the first one need to transfer heat in order to reach a thermal equilibrium with water. Then:
After a quick substitution, the expanded expression is:
The final temperature of the system is:
Answer:
The velocity of mass 2m is
Explanation:
From the question w are told that
The mass of the billiard ball A is =m
The initial speed of the billiard ball A = =1 m/s
The mass of the billiard ball B is = 2 m
The initial speed of the billiard ball B = 0
Let the final speed of the billiard ball A =
Let The finial speed of the billiard ball B =
According to the law of conservation of Energy
Substituting values
Multiplying through by
According to the law of conservation of Momentum
Substituting values
Multiplying through by
making subject of the equation 2
Substituting this into equation 1
Multiplying through by
Answer:
Explanation:
Given:
- spring constant of the spring attached to the input piston,
- mass subjected to the output plunger,
<u>Now, the force due to the mass:</u>
<u>Compression in Spring:</u>
or