Suppose that a cannon is used to launch a projectile into Earth orbit as Newton proposed. Assume that the cannon accelerates its shell at 20 times the acceleration due to gravity and achieves orbital velocity of 8000m/s. How long must the cannon be?

(A) 8000m. (B) 80,000m. (C) 160,000m. (D) 10m.

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Questions --- What this question is about

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21.6

Suppose that a cannon is used to launch a projectile into Earth orbit as Newton proposed. Assume that the cannon accelerates its shell at 20 times the acceleration due to gravity and achieves orbital velocity of 8000m/s. How long must the cannon be?

(A) 8000m. --- No.

The acceleration is 200m/s.

Try again.

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Questions --- What this question is about

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21.6

Suppose that a cannon is used to launch a projectile into Earth orbit as Newton proposed. Assume that the cannon accelerates its shell at 20 times the acceleration due to gravity and achieves orbital velocity of 8000m/s. How long must the cannon be?

(B) 80,000m. --- No.

Remember the factor of 2 in the formula: v=2ad.

Try again.

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Questions --- What this question is about

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21.6

Suppose that a cannon is used to launch a projectile into Earth orbit as Newton proposed. Assume that the cannon accelerates its shell at 20 times the acceleration due to gravity and achieves orbital velocity of 8000m/s. How long must the cannon be?

(C) 160,000m. --- Yes.

d = v/(2a) = (8000m/s)/(400m/s)
= (64,000,000)/(400) m = 160,000m.

Try again.

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Questions --- What this question is about

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21.6

Suppose that a cannon is used to launch a projectile into Earth orbit as Newton proposed. Assume that the cannon accelerates its shell at 20 times the acceleration due to gravity and achieves orbital velocity of 8000m/s. How long must the cannon be?

(D) 10m. --- No.

Remember to multiply the velocity by itself to get the velocity squared.

Try again.

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Questions --- What this question is about

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21.6