Answer:
0.75
Explanation:
Since the static frictional force is the maximum force applied just before sliding, our frictional force, F is 300 N.
Since F = μN where μ = coefficient of static friction and N = normal force = 400 N (which is the downward force applied against the surface).
So, μ = F/N
= 300 N/400 N
= 3/4
= 0.75
So, the coefficient of static friction μ = 0.75
Answer:
B). 3.4 s
Explanation:
As we can see the graph is given between velocity and time
so here we can see that the velocity is changing here with time and initially for some time it moves with constant speed
Then it's speed decreases to next few second and then speed increases to its maximum value
The time after which velocity comes to its maximum value will reach after t = 3 s
so out of the all given options most correct option will be
When the bus starts moving forward, the man remains at rest,
causing him to lean back.
When the bus slows down, the man continues to move forward,
and appears to lean forward.
Both events are examples of the effect of inertia.
Answer:
The horizontal displacement of the arrow is not larger than the banana split.
Explanation:
Using y - y₀ = ut - 1/2gt², we find the time it takes the arrow to drop to the ground from the top of mount Everest.
So, y₀ = elevation of Mount Everest = 29029 ft = 29029 × 1ft = 29029 × 0.3048 m = 8848.04 m, y = final position of arrow = 0 m, u = initial vertical speed of arrow = 0 m/s, g = acceleration due to gravity = 9.8 m/s² and t = time taken for arrow to fall to the ground.
y - y₀ = ut - 1/2gt²
0 - y₀ = 0 × t - 1/2gt²
-y₀ = -1/2gt²
t² = 2y₀/g
t = √(2y₀/g)
Substituting the values of the variables, we have
t = √(2y₀/g)
= √(2 × 8848.04 m/9.8 m/s²)
= √(17696.08 m/9.8 m/s²)
= √(1805.72 s²)
= 42.5 s
The horizontal distance the arrow moves is thus d = vt where v = maximum firing speed of arrow = 100 m/s and t = 42.5 s
So, d = vt
= 100 m/s × 42.5 s
= 4250 m
= 4.25 km
Since d = 4.25 km < 7.32 km, the horizontal displacement of the arrow is not larger than the banana split.
Answer:
Một dây dẫn bằng nikelin dài 20m, tiết diện 0.5mm2 điện trở suất của nikelin là 0,4.10^-6 ôm/m. tính điện trở dây dẫn
