QLD-Physics - Unit 3 - Test 2

A frictionless inclined plane is raised at one end to a height (h) and the acceleration of a cart is measured at each height.  Determine which diagram in Figure 1 best shows the acceleration (a), of the cart as a function of height.

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A frictionless inclined plane is raised at one end to a height (h) and the acceleration of a cart is measured at each height.  Determine which diagram in Figure 1 best shows the final velocity (v),of the cart as a function of height.

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A 1kg object is placed on a frictionless incline set at an angle ϴ.  Select the expression that best describes its acceleration.

• mg sinϴ

• mg cosϴ

• g sinϴ

• g cosϴ

Determine how many times heavier by weight would a person be on Jupiter than on Earth

(NOTE: g_Jupiter = 25ms^-2)

_{(Answer to 2 d.p.)}

The block in the diagram weighs 50N.  The applied force F_A is 20N. Calculate the normal force. (Answer to 1 d.p. and include units without spaces between numbers and units).

A student investigated centripetal motion by whirling a rubber stopper above his head in a horizontal circle at constant speed.  The student keeps the mass (m) of the rubber stopper constant, but increases the hanging slotted masses (M).  Which statement best describes what he can do to keep the radius constant.

• increase m or v

• increase m or decrease v

• decrease m or increase v

• decrease m or v

A student investigated centripetal motion by whirling a rubber stopper above his head in a horizontal circle at constant speed.  If the rubber stopper moved in an anticlockwise direction, which diagram best shows the direction of the velocity and acceleration at point x?

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An object will travel the circumference of a circle in one period (T) of time if it is in uniform circular motion. 

• TRUE

• FALSE

A ball on a string is swirled around in a horizontal circle at a constant speed of 2.5 m/s and experiences an acceleration of 3.9 m/s/s.  Calculate the radius of its motion. 

(Answer to 1 d.p. and include units with no spaces between numbers and units)

FORMULA: a_c= v²/r

You are driving a car around a corner and you are experiencing a force of 4500N against your seatbelt.  The radius of the curve is 30m and your mass is 60kg.  How fast must you be travelling?

(Answer to 1 d.p. and include units with no spaces between numbers and units) FORMULA: F_c= mv²/r