Answer:
6.0 ×
W/
Explanation:
From Wien's displacement formula;
Q = e A
Where: Q is the quantity of heat transferred, e is the emissivity of the surface, A is the area, and T is the temperature.
The emissive intensity =
= e
Given from the question that: e = 0.6 and T = 1000K, thus;
emissive intensity = 0.6 × 
= 0.6 × 1.0 × 
= 6.0 ×

Therefore, the emissive intensity coming out of the surface is 6.0 ×
W/
.
Answer:
0.0928km/min (4dp)
Explanation:
To find the jogger's speed in km per minute, we just need to divide the number of km jogged by the time in minutes it took to jog that distance. This will give us the distance they jogged every minute which is their speed.
4km in 32 minutes:
4/32 = 0.125km/min
2km in 22 minutes:
2/22 = 0.091 (3dp)km/min
1km in 16 minutes:
0.0625km/min
Now to find the average speed of these 3 speeds, we just add them all together and divide by how many values there are (3 values).
Average (mean) = 
Average = 0.2785/3
Average speed of jogger = 0.0928 (4dp) km/min
Hope this helped!
Answer:
um d. but I am guessing this ans
Answer:
just before landing the ground
Explanation:
Let the velocity of projection is u and the angle of projection is 30°.
Let T is the time of flight and R is the horizontal distance traveled. As there is no force acting in horizontal direction, so the horizontal velocity remains constant. Let the particle hits the ground with velocity v.
initial horizontal component of velocity, ux = u Cos 30
initial vertical component of velocity, uy = u Sin 30
Time of flight is given by

Final horizontal component of velocity, vx = ux = u Cos 30
Let vy is teh final vertical component of velocity.
Use first equation of motion
vy = uy - gT


vy = - u Sin 30
The magnitude of final velocity is given by


v = u
Thus, the velocity is same as it just reaches the ground.
Answer:
option B
Explanation:
given,
Force exerted by the hydraulic jack piston = F₁ = 250 N
diameter of piston, d₁ = 0.02 m
r₁ = 0.01 m
diameter of second piston, d₂ = 0.15 m
r₂ = 0.075 m
mass of the jack to lift = ?
now,




F₂ = 14062.5 N
F = m g


m = 1435 Kg
hence, the correct answer is option B