Answer:
Energy lost due to friction is 22 J
Explanation:
Mass of the ball m = 4 kg
Initially velocity of ball v = 6 m/sec
So kinetic energy of the ball 
Now due to friction velocity decreases to 5 m/sec
Kinetic energy become
Therefore energy lost due to friction = 72 -50 = 22 J
Answer:
The conditions necessary for hearing the echo. The distance between the sound source and the reflecting surface must not be less than 17 metres where the time period between hearing the original sound and its echo should not be less than 0.1 of a second.
Answer:
Mechanical advantage = 2.875
Explanation:
Given:
A diagram is shown below for the above scenario.
Length of ramp (Effort arm) = 4.6 m
Height of truck bed ( Resistance length) = 1.6 m
Mechanical advantage (MA) is the ratio of effort arm and resistance length.
So, mechanical advantage is given as,
Answer:
E) momentum and mechanical energy
Explanation:
In the context, an object is attached to the another mass with a spring which is initially at a rest position. Now when the spring is compressed, the two masses moves with the same speed. Now since the both the masses combines with the spring to move together they are considered as one system and in this case the momentum and the kinetic energy will be conserved.
The kinetic energy and momentum of the system after collision and the kinetic energy and momentum of the two masses before collision will be constant.
