When object travels with uniform velocity, no force acts on it. hence , yes.
Answer:
Power = 0.33 Watts
Explanation:
Given the following data;
Distance = 1m
Force = 20N
First of all, we would solve for the work done by the boy.
Workdone = force * distance
Substituting into the equation, we have;
Workdone = 20*1 = 20J
Now to find power;
Power = workdone/time
Power = 20/60
Power = 0.33 Watts.
Let's call the constant acceleration a.
At a time t, its speed will thus be v(t)=a*t+v0 where v0 is its initial speed, here 10 m/s. Hence v(t)=a*t+10.
From there we can deduce the position P(t)=a*t^2/2+10t+p0 where p0 is the initial position, here 0.
Hence P(t)=a*t^2/2+10t
Let's call T the time at which it's at 50 m/s, we know that P(T)=225m and that v(T)=50 m/s hence a*T+10=50 thus a=40/T and P(T)=(40/2+10)T=30T
Hence T=225/30=7.5
It took 7.5 seconds
Answer:
Explanation:
Diffraction grating is used to form interference pattern of dark and bright band.
Distance between adjacent slits (a ) = 1 / 420 mm
= 2.38 x 10⁻³ mm
2.38 x 10⁻⁶ m
wave length of red light
= 680 x 10⁻⁹ m
For bright red band
position x on the screen
= n λD / a , n = 0,1,2,3 etc
D = distance of screen
putting n = 1 , 2 and 3 , we can get three locations of bright red band.
x₁ = λD / a
= 680 x 10⁻⁹ x 2.8 / 2.38 x 10⁻⁶
= .8 m
= 80 cm
Position of second bright band
= 2 λD / a
= 2 x 80
= 160 cm
Position of third bright band
= 3 λD / a
= 3 x 80
= 240 cm
