The answer is 9.8 ms^-2, because there is only one force acting on the object so the acceleration will be numerically equal to the gravitational field strength.
Explanation:
It is given that, the height of a certain tower is 862 feet i.e to reach on the ground the object should travel, s = 862 feet
The distance traveled by a freely falling object is given by :



t = 7.34 seconds
So, the object will take 7.34 seconds to fall to the ground from the top of the building. Hence, this is the required solution.
Answer:
λ = 0.4 x 10⁻⁶ m = 400 nm
Explanation:
The relationship between frequency, wavelength and speed of an electromagnetic wave is given as follows:

where,
c = speed of light = 3 x 10⁸ m/s
f = frequency of the light wave = 7.5 x 10¹⁴ Hz
λ = wavelength of the light = ?
Therefore,

<u>λ = 0.4 x 10⁻⁶ m = 400 nm</u>
Answer:
The speed of the car when load is dropped in it is 17.19 m/s.
Explanation:
It is given that,
Mass of the railroad car, m₁ = 16000 kg
Speed of the railroad car, v₁ = 23 m/s
Mass of additional load, m₂ = 5400 kg
The additional load is dropped onto the car. Let v will be its speed. On applying the conservation of momentum as :



v = 17.19 m/s
So, the speed of the car when load is dropped in it is 17.19 m/s. Hence, this is the required solution.