Answer:
970.2 N
Explanation:
We are given that
Length of ladder=2.7 m
Mass,M=11 kg
Coefficient of friction=

Mass of painter=8M
Distance from base=d
We have to find the magnitude of the normal force exerted by the floor on the ladder.
Normal force exerted by floor on the ladder=
Where 
Normal force exerted by floor on the ladder=
31 m/s ÷ 9 m/s² = 3.44 s
Time = Change in velocity divided (÷) by acceleration.
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.
Waves can be described using a number of different characteristics of a wave. Wavelength and frequency are two such characteristics. The relationship between wavelength and frequency is that the frequency of a wave multiplied by its wavelength gives the speed of the wave