When a driver presses the brake pedal his car stops with an exhilaration -20
Answer:
the instrument that gives this precision is the micrometer screw
Explanation:
The high precision measurements of small parts are the general vernier and the micrometer screw.
In these two instruments the same principle is used: there is a fixed rule and a mobile one that increases precision.
Let's analyze the absolute error or precision of each instrument
* For the vernier, the precision of the fixed rule is 1 mm and there are 20 divisions (the most common); therefore the precision of the instrument is
Δx = 1 mm / 20
Δx = 0.05 mm
* For the micrometer screw, the precision of the fida rule is 0.5 mm and the number of divisions is 50, therefore the precision of the screw is
Δx = 0.5mm / 50
Δx = 0.01 mm
consequently the instrument that gives this precision is the micrometer screw
In Linear motion the swimmer swims
It's hard to tell exactly what's happening in that 110 cm that you marked over the wave. What is under the ends of the long arrow ? How many complete waves ? I counted 4.5 complete waves ... maybe ?
If there are 4.5 complete waves in 110cm, then the length of 1 wave is (110/4.5)=24.44cm.
Frequency = speed/wavelength
Frequency = 2m/s /0.2444m
Frequency = 8.18 Hz
Answer:
Fnet = 0
Explanation:
- Since the block slides across the floor at constant speed, this means that it's not accelerated.
- According Newton's 2nd Law, if the acceleration is zero, the net force on the sliding mass must be zero.
- This means that there must be a friction force opposing to the horizontal component of the applied force, equal in magnitude to it:
- In the vertical direction, the block is not accelerated either, so the sum of the normal force and the vertical component of the applied force, must be equal in magnitude to the force of gravity on the block:
⇒ 169 N + Fn = Fg = 216 N (3)
- This means that there must be a normal force equal to the difference between Fappy and Fg, as follows:
- Fn = 216 N - 169 N = 47 N (4)
