An echo
Refraction
Diffraction
Transmission
reflection
Answer:
a. P.E = 3430Joules.
b. Workdone = 3430Nm
Explanation:
<u>Given the following data;</u>
Mass = 70kg
Distance = 5m
We know that acceleration due to gravity is equal to 9.8m/s²
To find the potential energy;
Potential energy = mgh
P.E = 70*9.8*5
<em>P.E = 3430J</em>
b. To find the workdone;
Workdone = force * distance
But force = mass * acceleration
Force = 70*9.8
Force = 686 Newton.
Workdone = 686 * 5
<em>Workdone = 3430Nm</em>
Answer: Work W = 0
Explanation: Work W = F·s. Because rock does not move, s = 0 and
work done is zero.
If net external force acting on the system is zero, momentum is conserved. That means, initial and final momentum are same → total momentum of the system is zero.
Answer
given,
before collision
mass of car A = m_a = 1300 kg
velocity of car A = v_a = 35 mph
mass of car B = m_b= 1000 kg
velocity of car B = v_b = 25 mph
after collision
V_a = 30 mph
V_b = 31.5 mph
Initial momentum
final momentum
here initial momentum is equal to the final momentum of the car.
hence, momentum is conserved in the collision.
