If the motorist travelled at 20 meters a second for three minutes, 3 minutes is the same as 180 seconds, you multiply 20 times 180, which equals 3600, add 25, and the answer is 3625.
Answer:
Wavelength of the x rays is 
Explanation:
It is given that,
The inter planer spacing between the crystal planes, 
The first-order maximum in the Bragg reflection occurs when the incident and reflected x rays make an angle of 39.4 degrees with the crystal planes. According to the Bragg's condition, the first-order maximum is given by :
n = 1
So, the wavelength of the x rays is 
. Hence, this is the required solution.
<h3><u>Answer</u>;</h3>
D. 3600 N
<h3><u>Explanation</u>;</h3>
Mechanical advantage is the ratio of force output from a machine divided by the force input into the machine.
That is;
Mechanical advantage = Output Force/Input Force
In this case;
Input force = 800 N
Thus; Output force = M. A × input force
= 4.5 × 800
= 3600 N
Therefore; the output force by the machine is 3600 N
Answer:
The ball will reach the ground in 0.8s
Option C
Explanation:
Given:
- Takes t = 0.8 s for ball to reach ground when thrown horizontal from top of a building.
Find:
If it had been thrown with twice the speed in the same direction, it would have hit the ground in how many second.
Solution:
- We know that the amount of time taken to hit the ground is determined by the vertical distance i.e height at which it is thrown. The displacement of ball from top is given by:
S_y = S_o + V_i,y*t + 0.5*g*t^2
- We know that the S_o = height of the building.
We also know that the ball os thrown horizontally; hence, y-component of initial velocity is zero. V_y,i = 0
0 = h + 0 + 0.5*g*t^2
- Hence, the time taken t is:
t = sqrt ( 2h / g)
- The time taken to reach the ground is independent of the initial speed. Hence, the ball will reach the ground in 0.8s .
