Answer:
mu = 0.56
Explanation:
The friction force is calculated by taking into account the deceleration of the car in 25m. This can be calculated by using the following formula:
v: final speed = 0m/s (the car stops)
v_o: initial speed in the interval of interest = 60km/h
= 60(1000m)/(3600s) = 16.66m/s
x: distance = 25m
BY doing a the subject of the formula and replace the values of v, v_o and x you obtain:
with this value of a you calculate the friction force that makes this deceleration over the car. By using the Newton second's Law you obtain:
Furthermore, you use the relation between the friction force and the friction coefficient:
hence, the friction coefficient is 0.56
On ground weight of plane will be measured as its actual weight which will be given as
now when plane is in air its weight is measured as combined effect of earth gravitational force and buoyancy force both
so weight in air will be given as
here since net effect due to air is opposite to the direction of weight so in air the plane weight will be measure less than its weight on ground.
so answer will be
A)more than a plane in the air
C. Use a longer wrench, this is because it would create a greater turning moment as moment=force*distance
Answer:
r = 0.728 m
Explanation:
The intensity is defined as the ratio between the power per unit area
I = P / A
Where A is the area of the sphere where the wave is
A = 4π r²
In this exercise we are given the power of the P = 10.0 W micro waves, the safe intensity I₁ = 1.5 W / m²
A₁ = P / I₁
Calculate
A₁ = 10.0 / 1.5
A₁ = 6.6667 m²
Let's clear the radius of the sphere
r = √ A / 4π
r = √ (6.6667 / 4π)
r = 0.728 m
Answer:
b) the length of car
Explanation:
This is because 520 divided by 343 m/s.) would equal the length of a car.
