Explanation:
In a collision between two objects, both objects experience forces that are equal in magnitude and opposite in direction
Answer: There is not work done at the door because the door did not move.
Explanation: Work is defined as the movement done by a force.
So if you move to apply a force F in an object and you move it a distance D, the work applied on the object is
W = F*D
In this case, the secret agent pushes against the door, so there is a force, but the agent does not move the door, so D = 0, so there is no motion of the door, which implies that there is no work done at the door.
Given: Velocity of light c = 3.00 x 10⁸ m/s
Frequency f = 7.65 x 10⁷/s
Required: Wavelength λ = ?
Formula: λ = c/f
λ = 3.00 x 10⁸ m/s/7.65 x 10⁷/s
λ = 3.92 m
Yes that's a true statement. That's why grandmother put a hot water bottle to warm up her bed, and not a hot bar of steel or lead.