Answer:
Explanation:
False
When two waves overlap or superimpose over each other then they either undergo Constructive or destructive interference.
waves are the disturbance created by a force and add up to gives constructive interference when they are in the same line i.e. in the same phase.
When these disturbances are in the opposite phase then they superimpose to give destructive interference where the amplitude of the resulting wave will be much smaller as compared to original waves.
Answer
given,
initial velocity of skateboard = 5.1 m/s
angle above the horizontal = 55°
height of the ramp = 1 m
a) maximum height of projectile


H = 0.889 m
the maximum height of the skateboard above the ground
= 1 + 0.889
= 1.889 m
b) time to reach the height
t = 0.426 s
horizontal distance = u cos θ × t
= 5.1 × cos 55° × 0.426
horizontal distance = 1.25 m
Answer:
120,000J
Corrected question;
In one hour, coal supplies 500 000 J of energy. The wasted energy amounts to 380 000 J. How much useful energy is produced in one hour?
Explanation:
Given;
Total energy Et = 500,000 J
Wasted Energy Ew = 380,000J
The amount useful energy is the amount of energy that is available for supply.
This can be derived by subtracting the wasted energy from the total energy.
Useful energy = Total Energy - wasted energy
Eu = Et - Ew
Substituting the given values;
Eu = 500,000J - 380,000
Eu = 120,000 J
The amount of useful energy produced in one hour is 120,000 J
Conservation of energy explains that energy can only be transferred between different forms of energy
It depends when you look at a pichture it could possibly help.