Multi choice Question 1...lame.. (1 Viewer)

[peeasoup]

I put 'A', for the answer. It seemed right. I cant really remember what it asked, but, i think i can remember that the max height was the same, so the velocity was the same.

 

[Gomer]

The correct answer is B.

Both shots have the same height. They need to have different initial velocities as they have different angles. Say one shot had an angle of 30º and the other 40º and the intial velocity of each was 10m/s. The shot at 40º with respect to the horizon would have a greater initial vertical velocity than the shot at 30º. Therefore it would go higher into the air. But in the diagram it doesn't. Therefore the initial velocity of each shot would need to be different for each shot for them both to reach an equal height as they do.

Make sense? *shrugs*

Remember answer B is initial velocity, not the initial vertical velocity.

I am probably wrong, but i answered B so i am defending it.

-- Gomer

 

[budj]

Yeh i put A, a stupid mistake really. If you derive the equations for max heigt, i think its
(v^2Sin(theta)^2)/2g, Now most obviously theta angle differs, g is constant, and therefore to establish the equality between the two, V must differ

 

[Jezzabelle]

Yeh i put A, a stupid mistake really. If you derive the equations for max heigt, i think its
(v^2Sin(theta)^2)/2g, Now most obviously theta angle differs, g is constant, and therefore to establish the equality between the two, V must differ

its b. stop whinging you idiots who put A and get on with life

 

[Cactus]

OK I have seen some people here who have said the correct answer is B, but some others arent convinced. Time of flight is to do with the vertical motion of the object. They 2 trajectories had the same maximum height, therefore they had the same time of flight. So the only thing that was different was the initial velocity (Remember velocity is composed of a magnitude AND direction. The vertical magnitude of the initial velocity was the same in both flightpaths)

 

[Willmaker]

Straight after the exam finished, I showed the MC questions to my physics teachers and without hesitatiion he said B. Anyone with half a brain could have worked it out. No offense

 

[Jase]

As much as i would love it to be A, that being my answer, it is in fact B.

 

[lucyinthehole]

Anyone with half a brain could have worked it out. No offense

oh, none taken
i guess i'll just go watch some tv with my less than half a brain

wanker

 

[ShaunSmith]

Hahaha I Was Right Yay!

 

[withoutaface]

Time of flight is the same because the peaks of flight are at the same height, the answer is initial velocity.

 

[Tredanse]

The way I figured it to be B was an example our Physics teacher gave us ages ago:

If you stand at a cliff and simultaneously throw a rock out horizontally with one hand, and drop one from the other hand, they'll hit the water at the same time.

Regardless of horizontal velocity, the vertical velocity will be the same for both rocks at any given time, changing at a constant acceleration of 9.8ms^-2. So they'll hit the water together at the same time.

Because the max height of the cricket ball is the same, it's practically the same as the two rocks off the cliff. Answer is B.

 

[blackbunny]

its a caz if it is initial velocity the vertical displacement would be different but with time the DeltaY are the same