Home > Physics > Projectile Motion

In a TV set, an electron beam moves with horizontal velocity of 4.2 × 107 m/s across the cathode ray tube and strikes the screen, 41 cm away. The acceleration of gravity is 9.8 m/s How far does the electron beam fall while traversing this distance (in m)?

Answer 1

Layla Ahmed

#sf(4.9xx10^(-18)color(white)(x)m)#

We can get the time of flight from the horizontal component, which is constant:

#sf(t=0.41/(4.2xx10^(-7))=9.762xx10^(-9)color(white)(x)s)#

Now we can consider the vertical component:

#sf(s_y=1/2"g"t^2)#

#sf(s_y=1/2xx9.8xx(9.762xx10^(-9))^2=4.862xx10^(-18)color(white)(x)m)#

#sf(s_y=4.9color(white)(x)"am")#

This must be an old question as I don't think there are many cathode ray t.v sets around anymore.

By signing up, you agree to our Terms of Service and Privacy Policy

Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.