Answer:
Force, F = 77 N
Explanation:
A child in a wagon seem to fall backward when you give the wagon a sharp pull forward. It is due to Newton's third law of motion. The forward pull on wagon is called action force and the backward force is called reaction force. These two forces are equal in magnitude but they acts in opposite direction.
We need to calculate the force is needed to accelerate a sled. It can be calculated using the formula as :
F = m × a
Where
m = mass = 55 kg
a = acceleration = 1.4 m/s²

F = 77 N
So, the force needed to accelerate a sled is 77 N. Hence, this is the required solution.
Answer:
time taken by the wave to reach the person is 0.2 s
Explanation:
As we know that the speed of the wave is given as

here we know that the wavelength of the wave is


now speed of the wave is given as


Now time taken by the wave to reach 5 m distance is



When placing the piece of aluminium in water, the level of water will rise by an amount equal to the volume of the piece of aluminum.
Therefore, we need to find the volume of that piece.
Density can be calculated using the following rule:
Density = mass / volume
Therefore:
volume = mass / density
we are given that:
the density = 2.7 g / cm^3
the mass = 16 grams
Substitute in the equation to get the volume of the piece of aluminum as follows:
volume = 16 / 2.7 = 5.9259 cm^3
Since the water level will rise to an amount equal to the volume of aluminum, therefore, the water level will rise by 5.9259 cm^3
Precisely around 1,800 miles below.