I believe that the answer is B. 133 N
Answer:
57 N
Explanation:
Were are told that the force
of gravity on Tomas is 57 N.
And it acts at an inclined angle of 65°
Thus;
The vertical component of the velocity is; F_y = 57 sin 65
While the horizontal component is;
F_x = 57 cos 65
Thus;
F_y = 51.66 N
F_x = 24.09 N
The net force will be;
F_net = √((F_y)² + (F_x)²)
F_net = √(51.66² + 24.09²)
F_net = √3249.0837
F_net = 57 N
Answer:
Explanation:
Here image distance is fixed .
In the first case if v be image distance
1 / v - 1 / -25 = 1 / .05
1 / v = 1 / .05 - 1 / 25
= 20 - .04 = 19.96
v = .0501 m = 5.01 cm
In the second case
u = 4 ,
1 / v - 1 / - 4 = 1 / .05
1 / v = 20 - 1 / 4 = 19.75
v = .0506 = 5.06 cm
So lens must be moved forward by 5.06 - 5.01 = .05 cm ( away from film )
Answer:
1) f= 8.6 GHz
2) t= 0.2 ms
Explanation:
1)
- Since microwaves are electromagnetic waves, they move at the same speed as the light in vacuum, i.e. 3*10⁸ m/s.
- There exists a fixed relationship between the frequency (f) , the wavelength (λ) and the propagation speed in any wave, as follows:
- Replacing by the givens, and solving for f, we get:
⇒ f = 8.6 Ghz (with two significative figures)
2)
- Assuming that the microwaves travel at a constant speed in a straight line (behaving like rays) , we can apply the definition of average velocity, as follows:
where v= c= speed of light in vacuum = 3*10⁸ m/s
d= distance between mountaintops = 52 km = 52*10³ m
⇒ t = 0.2 ms (with two significative figures)
Answer:
a = (v2 - v1) / t
From A to B (8 - 4) m/s / 1 s = 4 m / s^2
From A to D ( 7 - 4) m/s / 5 s = .6 m / s^2
Note these equations hold for "uniform" values
They say nothing about the acceleration at intermediate points - the equation just says that his average speed increased from 4 m/s to 7 m/s during a 5 sec period
